Juan de Oñate
Oñate, Juan de (c.1549–1628), Spanish explorer of the American southwest.
21st Century Webster's Family Encyclopedia - Olympic Mountains to Palermo
Eugene Gladstone O'Neill
O'Neill, Eugene Gladstone (1888–1952), U.S. playwright, winner of the 1936 Nobel Prize for literature and several Pulitzer Prizes.
Thomas Philip (“Tip”) O'Neill Jr.
O'Neill, Thomas Philip (“Tip”), Jr. (1912–94), U.S. legislator.
Leonora O'Reilly
O'Reilly, Leonora (1870–1927), U.S. women's rights activist, instrumental in developing the National Women's Trade Union League for protection of women workers' rights (1903) and in establishing the National Association for the Advancement of Colored People (NAACP).
Olympic Mountains
Olympic Mountains, part of the Pacific Coast Range in northwest Washington.
Olympic National Park
Olympic National Park, scenic region established in Washington State in 1938.
Omaha
Omaha, Siouan-speaking Native American tribe of North America.
Omaha
Omaha (pop. 618,262), largest city in Nebraska, on the west bank of the Missouri River, established in 1854 after the Omaha Indians and U.S. government signed a peace treaty (1852).
Oman
Oman (formerly Muscat and Oman), independent sultanate on the southeast coast of the Arabian peninsula.
Omar Khayyam
Omar Khayyam (1048–1131), Persian poet, astronomer, and mathematician.
Ombudsman
Ombudsman, official appointed to investigate complaints by citizens against government officials or agencies.
Omdurman
Omdurman (pop. 526,800), largest city in Sudan, on the White Nile, established in 1885 by Muhammad Ahmed, who is entombed here.
Ommatidium
Ommatidium See: Compound eye.
Omnibus bill
Omnibus bill, legislation that includes many nonrelated bills lumped into 1 cumbersome package.
Omsk
Omsk (pop. 1,159,000), industrial city in Siberia, Russian Federation, about 1,360 m (2,190 km) east of Moscow.
Onager
Onager (Equus hemionus), wild relative to the donkey found in Asia.
Aristotle Socrates Onassis
Onassis, Aristotle Socrates (1906–75), Greek shipping magnate since the early 1930s.
Oncology
Oncology, branch of medicine concerned with the diagnosis and treatment of cancer, and research into its causes.
Oneida
Oneida, smallest of the original 5 nations of the Iroquois Confederacy.
Oneida Community
Oneida Community, religious commune founded by J.
Onion
Onion (Allium cepa), biennial or perennial plant of either the amaryllis or the lily family.
Onondaga
Onondaga, name of one of the original five nations of the Iroquois Confederacy, living in what is now New York.
Ontario
Ontario, most populous and wealthiest province in Canada. It is the nation's leader in manufacturing, mining, and agriculture. Ottawa, the nation's capital, and Toronto, the province's capital and the nation's second-largest city, are located in Ontario. The economic heart of Canada, Ontario accounts for 40% of the nation's productive capacity. Its industr…
Onyx
Onyx, hard form of quartz made up of extremely small crystals.
Oostende
Oostende See: Ostend.
Ooze
Ooze, any mud deposit, but especially that found on the ocean floor, often made up primarily of the remains of plankton (microscopic sea plants and animals that float on the surface of the water).
Opal
Opal, cryptocrystalline variety of porous hydrated silica, deposited from aqueous solution in all kinds of rocks, and also formed by replacement of other minerals.
Alexander Ivanovich Oparin
Oparin, Alexander Ivanovich (1894– ), Russian biochemist whose hypothesis on the origin of life became rationale for others' research.
OPEC
OPEC See: Organization of Petroleum Exporting Countries.
Open-Door Policy
Open-Door Policy, policy of equal commercial rights for all nations involved in an area.
Open housing
Open housing, enforcement of equal rights provided by fair-housing laws.
Open shop
Open shop, business that does not restrict its employees to labor union members.
Opera
Opera, staged dramatic form in which the text is wholly or partly sung to an instrumental or orchestral accompaniment. It originated in 17th-century Italy, in an attempt to recreate Greek drama. Much early opera was a mere excuse for spectacle, but works by Claudio Monteverdi, Jean Baptiste Lully, and Henry Purcell advanced the art. Dramatic standards declined in the 18th century, despite fine wor…
Operetta
Operetta, light, amusing, semi-operatic form using spoken conversation and tuneful songs.
Ophthalmia
Ophthalmia, disease of the eye tissue, extremely serious and usually occurring from a wound, poison, or contamination, although it can also be acquired through birth.
Ophthalmology
Ophthalmology, branch of medicine and surgery concerned with diagnosing and treating diseases of the eye.
Ophthalmoscope
Ophthalmoscope, instrument for examining the retina and structures of the inner eye.
Opiate
Opiate, potent drug mixed with opium, used to relieve extreme pain, induce sleep, or control coughing.
Opinion poll
Opinion poll See: Public opinion.
Opium
Opium, narcotic extract derived from the immature fruits of the opium poppy, native to Greece and Asia Minor. The milky juice is refined to a powder that has a sharp, bitter taste. Drugs derived from opium include heroin, morphine, laudanum, and codeine. Because these drugs can cause severe physical and psychologic dependencies, their use outside the pharmaceutical industry is strictly controlled …
Opium War
Opium War (1839–42), fought in China by the British, the first in a series aimed at opening ports and gaining tariff concessions. The pretext was the burying of 20,000 chests of opium by the Chinese. China had banned the opium trade in 1799, but with the aid of corrupt Chinese officials British merchants still made enormous profits from it. British troops occupied Hong Kong in 1841, and the…
Opossum
Opossum, primitive arboreal marsupial of the Americas.
J(ulius) Robert Oppenheimer
Oppenheimer, J(ulius) Robert (1904–67), U.S. physicist who headed the Manhattan Project (1942–45) which developed the atomic bomb.
Opposition
Opposition, in astronomy, placement whereby 2 heavenly bodies are aligned with a third in a somewhat straight line.
Optic nerve
Optic nerve See: Eye.
Optical disc
Optical disc, thin, flat, circular plastic plate covered with a reflective substance that receives coded information from a laser beam to record sound, data, or pictures.
Optical fiber
Optical fiber See: Fiber optics.
Optical illusion
Optical illusion, visual distortion of reality.
Optics
Optics, branch of physical science that deals with vision and light: its properties and phenomena, its origin and effects, and its role as a medium of sight.
Optometry
Optometry, measurement and examination of the visual powers; the art and practice of testing the eyes by means of instruments or appliances for defects of vision in order to correct them with eyeglasses.
Oracle
Oracle, in ancient times, the answer by a god or goddess to a human questioner, or the shrine at which the answer was given, usually through a priest or priestess (also called oracles).
Oraibi
Oraibi See: Hopi.
Oral contraceptive
Oral contraceptive See: Birth control.
Oral surgery
Oral surgery See: Periodontitis.
Oran
Oran (pop. 663,500), Algerian port city about 225 mi (362 km) west of Algiers on the Mediterranean Sea.
Orange
Orange, tree (genus Citrus) of the rue family; also, the fruit of the tree.
Orange Free State
Orange Free State, province in the Republic of South Africa, with Bloemfontein as its capital.
Orange hawkweed
Orange hawkweed See: Devil's paintbrush.
Orange River
Orange River, South African river with dams along its course (1,300 mi/2,090 km) to generate hydroelectric power, plus canals and tunnels that control flooding and bring irrigation water to 750,000 acres (300,000 hectares).
Orange root
Orange root See: Goldenseal.
Orangemen
Orangemen, or Loyal Orange Institution, Protestant (chiefly Ulster) society that since the first (1795) lodge has identified with the Protestant ascendancy in Ireland and, more recently, union with Britain.
Orangutan
Orangutan, large, red, anthropoid ape (Pongo pygmaeus), native to the rain forests of Sumatra and Borneo.
Oratorio
Oratorio, musical composition for vocal soloists, chorus, and orchestra, usually with a religious subject.
Oratory
Oratory, also called rhetoric, skill in persuasive speaking, originating in Greece c.460 B.C.
Orbit
Orbit, path followed by 1 celestial body revolving under the influence of gravity about another.
Orcagna
Orcagna (1308–68), painter, sculptor, and architect of Florence, Italy, leading artist in the Byzantine Gothic style.
Orchestra
Orchestra, instrumental group of more than a few players.
Orchid
Orchid, plant of the large family Orchidaceae (15,000–30,000 species) that produces colorful and elaborate flowers.
Baroness Emmuska Orczy
Orczy, Baroness Emmuska (1865–47), Hungarian author best known for the French Revolution adventure novel The Scarlet Pimpernel (1905).
Order in Council
Order in Council, statement or instruction from the British crown rule usually set forth in times of emergency or great national threat and without initial Parliamentary consent.
Ordinance
Ordinance, rule, decree, or command usually prepared locally to maintain order and control in cities, towns, or settlements where constitutions or laws of command have not yet been prepared.
Ordovician
Ordovician, second period of the Paleozoic Era, c.500–440 million years ago, immediately following the Cambrian.
Ore
Ore, aggregate of minerals and rocks from which minerals (usually metals) can be extracted.
Oregano
Oregano See: Marjoram.
Oregon
Oregon, Pacific Coast state in the northwestern United States; bordered by Washington to the north, Idaho to the east, Nevada and California to the south, and the Pacific Ocean to the west. Oregon has 6 main land regions. In the west, along the coast, the Cascade Mountains in the north merge into the Klamath Mountains in the south. Just east of the Coast Range lies the narrow Willamette Lowland, t…
Oregon Caves National Monument
Oregon Caves National Monument, wildlife preserves and limestone caves located on 480 acres (192 hectares) in the Siskiyou Mountains of Oregon.
Oregon grape
Oregon grape, wild, flowering, low-growing evergreen plant producing small blue edible berries in the fall, of the family Berberidaceae (genus Mahonia).
Oregon Territory
Oregon Territory, in North American northwest, area south of the 49th parallel, excluding Vancouver Island.
Oregon Trail
Oregon Trail, pioneer wagon route between Independence, Mo., on the Missouri River, and the Columbia River region of the Pacific Northwest.
Francisco de Orellana
Orellana, Francisco de (c.1511–46), Spanish soldier and explorer of the Amazon River.
Orestes
Orestes, in Greek mythology, son of Agamemnon and Clytemnestra.
Carl Orff
Orff, Carl (1895–1982), German composer and music teacher.
Organ
Organ, musical instrument in which air is blown into pipes of different shape and size to produce a range of notes.
Organ Pipe Cactus National Monument
Organ Pipe Cactus National Monument, desert region in southwest Arizona named for that cactus which, with additional uncommon plants, is found only in this 517 sq mi (1,339 sq km) U.S. location.
Organ transplant
Organ transplant See: Tissue transplant.
Organic chemistry
Organic chemistry, branch of chemistry comprising the study of hydrocarbons, or carbon compounds containing hydrogen. (Simple carbon compounds such as carbon dioxide are usually considered inorganic.) Because of carbon's ability to form linked chains of atoms of any length and complexity, there are far more organic compounds than inorganic.
Organization of African Unity
Organization of African Unity (OAU), association of independent African states (excluding South Africa) that aims to promote unity among its members and improve economic and cultural relations in Africa.
Organization of American States
Organization of American States (OAS), association of republics of the Americas that aims to settle disputes peacefully, to create a collective security system, and to coordinate the work of other intra-American bodies.
Organization for Economic Cooperation and Development
Organization for Economic Cooperation and Development, OECD), international governmental body representing 29 countries, created in 1961 to develop trade and support and assist in each other's growth and economic welfare.
Organization of Petroleum Exporting Countries
Organization of Petroleum Exporting Countries (OPEC), group of 12 oil-producing countries that attempts to control oil prices in world sales.
Oriental exclusion acts
Oriental exclusion acts, edicts either limiting or halting immigration of Asians into the United States.
Origami
Origami, Japanese form of art made by folding various-sized squares of paper into birds, flowers, fish, and abstract shapes.
Origen
Origen (Origines Adamantius; A.D. 185?–A.D. 254?), one of the foremost radical theologians of the early Christian Church.
Orinoco River
Orinoco River, tributary of Venezuela, about 1,700 mi (2,736 km) long.
Oriole
Oriole, name of several members of the blackbird family.
Orion
Orion (the hunter), star constellation resembling the shape of a man, named from Greek mythology.
Orion
Orion, in Greek mythology, giant hunter killed by the goddess Artemis, who then turned him into a constellation.
Orizaba
Orizaba, or Citlaltépetl, Mexico's highest mountain and North America's third tallest, elevation 18,701 ft (5,700 m).
Orizaba
Orizaba (pop. 118,400), Mexican resort city located in a scenic valley between Veracruz and Mexico City.
Orkney Islands
Orkney Islands, group of about 70 islands north of Scotland, of which they are part.
Orléans
Orléans, family name of 2 branches of the French royal line.
Orléans
Orléans (pop. 108,100), city in the Loire Valley, northwest France.
Orlando
Orlando (pop. 1,072,748), resort city and retirement center in central Florida, with a year-round temperate climate for its fast-growing population.
Vittorio Emanuele Orlando
Orlando, Vittorio Emanuele (1860–1952), Italian statesman and prime minister (1917–19).
Eugene Ormandy
Ormandy, Eugene (Eugene Ormandy Blau; 1899–1985), Hungarian-born U.S. symphony conductor, music director of the Philadelphia Orchestra 1938–80.
Ornithischian
Ornithischian See: Dinosaur.
Ornithosis
Ornithosis See: Psittacosis.
Oroville Dam
Oroville Dam, transversing California's Feather River, providing flood control, irrigation, and hydroelectric power.
José Clemente Orozco
Orozco, José Clemente (1883–1949), Mexican painter.
Orpheus
Orpheus, in Greek mythology, renowned musician of Thrace.
Bobby Orr
Orr, Bobby (1948– ), Canadian-born, U.S. hockey player.
Orrisroot
Orrisroot, root body of 3 species of irises, which produce an oil with the fragrance of violets.
Daniel Ortega
Ortega, Daniel (1945– ), revolutionary leader of the Sandinista National Liberation Front in Nicaragua (1984–1990).
José Ortega y Gasset
Ortega y Gasset, José (1883–1955), Spanish philosopher whose best-known work, The Revolt of the Masses (1929), attributes Western decadence to the revolt of “mass man” against an intellectual elite.
Orthodontics
Orthodontics, in dentistry, correction or prevention of the arrangement or number of teeth in people and animals.
Orthopedics
Orthopedics, specialty within surgery dealing with bone and soft-tissue disease, damage, and deformity.
George Orwell
Orwell, George (Eric Arthur Blair; 1903–50), English writer, famous principally for Animal Farm (1945), a satire on communist revolution, and Nineteen Eighty-Four (1949), which depicts a dehumanizing totalitarian society.
Oryx
Oryx, genus of African antelopes with a white or fawn coat and long curving horns.
Osage
Osage, Native American tribe of the Siouan language group who lived in what is now western Missouri and Arkansas in the late 17th century.
Osage orange
Osage orange (Maclura pomifera), tree originally found only in Texas, Oklahoma, and Arkansas.
Osaka
Osaka (pop. 2,495,300), Japan's third-largest city, an industrial and commercial center, on Honshu Island at the mouth of the Yodo River on Osaka Bay.
Osborn
Osborn, family name of two American zoologists.
John Osborne
Osborne, John (1929–94), English dramatist whose Look Back in Anger (1956) made him the first Angry Young Man of the 1950s and established a new and vigorous realism in the British theater.
Oscar
Oscar See: Academy Awards®.
Osceola
Osceola (1804?–38), Native American leader in the Second Seminole War against the United States (1835–42).
Oscilloscope
Oscilloscope, device using a cathode ray tube to produce line graphs of rapidly varying electrical signals.
Oshawa
Oshawa (pop. 123,700), automobile-manufacturing city in Ontario, Canada, located east of Toronto on Lake Ontario.
Osier
Osier, tough, pliable twigs or branches from the willow family, used for weaving baskets or furniture.
Osiris
Osiris, ancient Egyptian god, brother and husband of Isis, and father of Horus.
Sir William Osler
Osler, Sir William (1849–1919), Canadian-born U.S. physician and educator who taught medical students the value of patient involvement.
Oslo
Oslo (pop. 473,300), capital, largest city and chief seaport of Norway.
Osmium
Osmium, chemical element, symbol Os; for physical constants see Periodic Table.
Osmosis
Osmosis, diffusion of a solvent through a semipermeable membrane that separates 2 solutions of different concentration.
Osprey
Osprey, large fish-eating bird of prey (Pandion haliaetus), found worldwide, except in South America.
Ostend
Ostend (pop. 69,100), port city in northwest Belgium on the North Sea.
Ostend Manifesto
Ostend Manifesto, document created in Ostend, Belgium, in 1854 by 3 proslavery U.S. diplomats, James Buchanan, John Y.
Osteomyelitis
Osteomyelitis, bacterial infection of bone, usually caused by staphylococcus, streptococcus, or salmonella carried to the bone by the blood or through open fractures.
Osteopathic medicine
Osteopathic medicine, method of therapy that concentrates on manipulation of bones and muscles, developed in 1874 by Andrew Taylor Still.
Osteoporosis
Osteoporosis, loss of bone mass and density.
Osteosclerosis
Osteosclerosis, abnormal hardening or thickening of the bone, causing brittleness and an inclination to fracture.
Ostrava
Ostrava (pop. 327,400), industrial city in northeastern Moravia, Czech Republic, about 170 mi (274 km) east of Prague.
Ostrich
Ostrich (Struthio camelus), the largest living bird, at one time found throughout Africa and southwest Asia but now common only in east Africa.
Ostrogoths
Ostrogoths (East Goths), branch of the Goths, a Germanic people who originally occupied the lands to the north of the Black Sea.
Aleksander Ostrovsky
Ostrovsky, Aleksander (1823–86), Russian dramatist whose plays, usually about merchants and minor officials, are marked by powerful characterization and strong drama.
Wilhelm Ostwald
Ostwald, Wilhelm (1853–1932), German physical chemist regarded as a father of physical chemistry, awarded the 1909 Nobel Prize for chemistry for his work on catalysis.
Lee Harvey Oswald
Oswald, Lee Harvey (1939–1963), the alleged assassin of President John F.
Oswego
Oswego, Great Lakes port city, on Lake Ontario and the Oswego River in New York, originally commanded by the British (1722–96) and incorporated in 1848.
Elisha Graves Otis
Otis, Elisha Graves (1811–61), U.S. inventor of the safety elevator (1852), first installed for passenger use in 1857.
James Otis
Otis, James (1725–83), American Revolutionary politician in the colonial conflict for independence from Great Britain.
Otoscope
Otoscope, instrument for examining the internal parts of the ear.
Ottawa
Ottawa (pop. 920,900), capital city of Canada, located at the junction of the Ottawa and Rideau rivers, near the southeastern tip of the province of Ontario. Across the Ottawa River is the twin city of Hull, Quebec. In 1968 the city of Ottawa was combined with a number of communities to form a regional government area called Ottawa-Carleton. Ottawa is principally concerned with the business of gov…
Ottawa
Ottawa, name of large North American Native American tribe of the Algonquian family originally inhabiting, with the Ojibwa and Potawatomi tribes, the region north of the Great Lakes.
Ottawa River
Ottawa River, principal tributary of the St.
Otter
Otter, aquatic or semiaquatic carnivore of the weasel family.
Otter hound
Otter hound, working dog, dating to 14th-century England, used for hunting otters.
Otto
Otto, name of 4 Holy Roman Emperors. Otto I the Great (912–73) was founder and first emperor of the Holy Roman Empire from 962. King of Saxony from 936, he invaded Italy and declared himself king of the Lombards (951). He subdued the Poles and Bohemians and routed the Magyars of Hungary (955). Otto was crowned emperor in Rome for helping Pope John XII against an Italian king, Berengar II. O…
Otto I
Otto I (1815–67), Austrian-born king of Greece (1833–62).
Ottoman Empire
Ottoman Empire, vast empire of the Ottoman Turks that at its height, during the reign of Sultan Suleyman I, stretched from the far shore of the Black Sea and the Persian Gulf in the east to Budapest in the north and Algiers in the west. The Ottoman Turks, led by Osman I, entered Asia Minor in the late 1200s and, expanding rapidly, made Bursa their capital in 1326. They crossed to the Balkan Penins…
Ouachita River
Ouachita River, in western Arkansas and eastern Louisiana, 605 mi (974 km) long, about 350 mi (563 km) of which is navigable.
Ouagadougou
Ouagadougou (pop. 442,200), capital of Burkina Faso, land of the Mossi people in western Africa.
Oubangui River
Oubangui River See: Ubangi River.
Ouida
Ouida (Maria Louise de la Ramée; 1839–1908), English novelist.
Outboard motor
Outboard motor, high-speed boat motor having 1 to 8 cylinders.
Richard Felton Outcault
Outcault, Richard Felton (1863–1928), U.S. cartoonist, originator of the Yellow Kid and Buster Brown comic strips.
Ouzel
Ouzel See: Dipper.
Ovary
Ovary, female reproductive organ.
Ovenbird
Ovenbird (Seiurus aurocapillus), member of the wood warbler family, a 6-in (15-cm) long bird whose grassy rounded nest, with a side opening built on the ground, resembles an adobe oven.
Overture
Overture, independent instrumental musical work, often serving as a prelude to a major musical presentation and including portions of that production's music.
Ovid
Ovid (Publius Ovidius Naso; 43 B.C.–A.D. 18), Latin poet.
Oviparous animal
Oviparous animal, one hatched from a fertilized egg that matured after being expelled from its parent's body.
Ovulation
Ovulation See: Reproduction.
Owen
Owen, 2 industrialists and social reformers.
Ruth Bryan Owen
Owen, Ruth Bryan (1885–1954), first U.S. woman diplomat, as minister to Denmark (1933–36).
Wilfred Owen
Owen, Wilfred (1893–1918), English poet, deeply influenced by Siegfried Sassoon, who wrote movingly of the savagery and human sacrifice in World War I.
Jesse Owens
Owens, Jesse (1913–80), U.S.
Owensboro
Owensboro (pop. 87,189), city in Kentucky, originally called Yellow Banks after the color of its site on the Ohio River.
Owl
Owl, nocturnal bird of prey of the family Tytonidae or the family Strigidae.
Owyhee Dam
Owyhee Dam, concrete arch gravity dam on Oregon's Owyhee River near the Idaho border, completed by the U.S.
Ox
Ox, term zoologically applied to many members of the family Bovidae; also, in common usage, a castrated bull used for draft purposes or for its meat.
Oxalic acid
Oxalic acid (COOH)2 ·H2O, colorless, poisonous, organic acid.
Oxalis
Oxalis, group of about 850 kinds of plants of the wood-sorrel family, occurring mostly in South Africa and South America.
Oxbow lake
Oxbow lake, shallow U-shaped or serpentine lake, formed from a riverbed when the river has changed to a straighter course.
Axel Gustaffson Oxenstierna
Oxenstierna, Axel Gustaffson (1583–1654), Swedish politician.
Oxford
Oxford (pop. 115,800), city of south-central England, the seat of Oxford University.
Oxford Movement
Oxford Movement, religious movement begun in 1833 in Oxford that aimed to revitalize the Church of England by reintroducing traditional Catholic practices and doctrines.
Oxford University
Oxford University, English university in Oxford comprising nearly 50 affiliated but autonomous colleges and halls, a great center of learning since its foundation in the 12th century.
Oxidation
Oxidation, any process that increases the proportion of oxygen or acid-forming element or radical in a compound.
Oxide
Oxide, chemical compound of oxygen and another element or, in the case of organic oxides, an organic compound.
G(arfield) Bromley Oxnam
Oxnam, G(arfield) Bromley (1891–1963), U.S.
Oxyacetylene
Oxyacetylene See: Acetylene.
Oxygen
Oxygen, chemical element, symbol O; for physical constants see Periodic Table.
Oxygen tent
Oxygen tent, enclosed space, often made of plastic, in which a patient is nursed in an atmosphere enriched with oxygen.
Oyster
Oyster, bivalve mollusk of shallow coastal waters.
Oyster plant
Oyster plant See: Salsify.
Oyster plant
Oyster plant See: Salsify.
Oystercatcher
Oystercatcher, any of a family (Haematopodidae) of shorebirds found in most parts of the world.
Oystercatcher
Oystercatcher, any of a family (Haematopodidae) of shorebirds found in most parts of the world.
Ozalid process
Ozalid process, trademarked photocopying process using Ozalid paper, which is chemically treated to receive an impression made by ultraviolet rays, and then developed by the Ozalid machine.
Ozalid process
Ozalid process, trademarked photocopying process using Ozalid paper, which is chemically treated to receive an impression made by ultraviolet rays, and then developed by the Ozalid machine.
Ozark Mountains
Ozark Mountains, plateau of rugged beauty in southern Missouri, northern Arkansas, and northeastern Oklahoma.
Ozark Mountains
Ozark Mountains, plateau of rugged beauty in southern Missouri, northern Arkansas, and northeastern Oklahoma.
Seiji Ozawa
Ozawa, Seiji (1935– ), Japanese conductor, best known for his fiery interpretations of Romantic and modern French composers.
Seiji Ozawa
Ozawa, Seiji (1935– ), Japanese conductor, best known for his fiery interpretations of Romantic and modern French composers.
Ozone
Ozone, O3, triatomic oxygen; a blue gas with a pungent odor.
Ozone
Ozone, O3, triatomic oxygen; a blue gas with a pungent odor.
P
P, 16th letter of the English alphabet, corresponding with the letter pe of the Semitic alphabet, which was represented by a diamond-shaped symbol based on the Egyptian hieroglyph for “mouth.” The Greeks adopted the letter as pi, and it took its modern form in Latin.
José Antonio Paéz
Paéz, José Antonio (1790–1873), Venezuelan soldier and president.
Paca
Paca, any of a genus (Cuniculus) of large, nocturnal, plant-eating rodents of the tropical forests of North and South America.
William Paca
Paca, William (1740–99), U.S. political leader, signer of the Declaration of Independence.
Pacemaker
Pacemaker, small mass of cells in the right atrium of the heart that gives rise to the electrical impulses that initiate contractions of the heart; also called sinoatrial (S-A) nodes.
Pacific Islands
Pacific Islands, also Oceania, consisting of the 20,000 to 30,000 islands scattered over thousands of square miles of the Pacific Ocean. The outer limits of Oceania, known as the Pacific Rim, are defined by the archipelagos of Indonesia, the Philippines, and Japan on the Asian side, and by the Aleutians, Galapagos, and other island groups close to the northern and southern continents on the Americ…
Trust Territory of the Pacific Islands
Pacific Islands, Trust Territory of the, trust territory of the UN administered by the United States (1946–81).
Pacific Ocean
Pacific Ocean, world's largest and deepest ocean, extending from the Arctic to the Antarctic oceans and from the Americas to Asia, covering an area of about 70 million sq mi (181.3 million sq km), or one-third of the earth's total surface.
Pacific scandal
Pacific scandal (1873), corruption charges against Canadian prime minister John Macdonald.
Pacifism
Pacifism, belief that violence is never justified and hence that peaceful means should always be employed to settle disputes.
Pack rat
Pack rat See: Wood rat.
Paddlefish
Paddlefish, any of various freshwater relatives of the sturgeon, resembling a shark with a long, paddlelike snout.
Ignace Jan Paderewski
Paderewski, Ignace Jan (1860–1941), Polish concert pianist, composer, and politician.
Padua
Padua (pop. 213,700), oldest city in northern Italy, on the Bacchiglione River, 22 mi (35 km) southwest of Venice.
Paducah
Paducah (pop. 29,315), river port city in southwestern Kentucky, on the Tennessee and Ohio rivers, at the head of the Tennessee-Tombigbee Waterway, which extends to the Gulf of Mexico.
Paestum
Paestum, ancient city (fl. 6th century B.C.) situated south of Salerno, southern Italy.
Pagan
Pagan, volcanic island in the western Pacific Ocean, one of the Mariana islands.
Niccolò Paganini
Paganini, Niccolò (1782–1840), Italian virtuoso violinist.
Page
Page See: Knights and knighthood.
Geraldine Page
Page, Geraldine (1924–87), U.S. stage, film, and television actress.
Marcel Pagnol
Pagnol, Marcel (1895–1974), French playwright, screenwriter, director, producer, and critic.
Pago Pago
Pago Pago See: American Samoa.
Mohammad Reza Pahlavi
Pahlavi, Mohammad Reza See: Mohammad Reza Pahlavi.
Reza Shah Pahlavi
Pahlavi, Reza Shah See: Reza Shah Pahlavi.
Satchel Paige
Paige, Satchel (Leroy Robert Paige; 1906–1982), U.S. baseball pitcher.
Robert Treat Paine
Paine, Robert Treat (1731–1814), American lawyer, signer of the Declaration of Independence.
Thomas Paine
Paine, Thomas (1737–1809), English-born writer and radical, a leading figure of the American Revolution.
Paint
Paint, fluid applied to a surface in thin layers, forming a colored, solid coating for decoration, representation, or protection.
Painted Desert
Painted Desert, brightly colored barren region about 150 mi (241 km) long of mesas and plateaus in north central Arizona, east of the Little Colorado River.
Painted-tongue
Painted-tongue, or salpiglossis, flowering garden annual (Salpiglossis sinuata) of the nightshade family.
Painter's colic
Painter's colic, or lead colic, symptom of lead poisoning characterized by severe abdominal pain.
Painting
Painting, depiction by means of line and color of a subject, rendered representationally or abstractly, on a 2-dimensional surface. The art of painting dates from more than 20,000 years ago, with cave paintings of animals and hunters, to ancient Egyptian tomb paintings, Cretan celebratory paintings on buildings, and the painted pottery of the Greeks. The Romans were the first to paint lifelike fig…
Paisley
Paisley (pop. 203,400), industrial city in western Scotland near Glasgow, on the White Cart River.
Paiute
Paiute, several Native American tribes of the Shoshone group.
Pakistan
Pakistan, Islamic Republic of Pakistan, nation state on the Indian subcontinent. Pakistan covers about 307,374 sq mi (796,095 sq km) and is bordered on the west by Iran, on the northwest by Afghanistan, on the southeast by India, and on the south by the Arabian Sea. Pakistan is dominated by the mountains of the Hindu Kush in the north, but there are fertile valleys in the northwest. The west is ar…
Palate
Palate, bodily structure dividing the mouth from the nose and bounded by the upper gums and teeth; it is made of bone and covered by mucous membrane.
Palatinate
Palatinate, 2 regions of Germany: the Lower, or Rhine, Palatinate is on the Rhine River bordering France and the Saar; the Upper Palatinate is in northeastern Bavaria.
Palau Islands
Palau Islands (Belau), independent group of coral and volcanic islands in the western Pacific Ocean.
Paleocene
Paleocene, first epoch of the Tertiary period, c.65–55 million years ago.
Paleogeography
Paleogeography, science of the construction from geologic, paleontologic, and other evidence of maps of the earth's surface at specific times in the past.
Paleography
Paleography, the study of handwritten material from the ancient and medieval times.
Paleolithic Period
Paleolithic Period See: Stone Age.
Paleontology
Paleontology, study of fossils.
Paleozoic
Paleozoic, earliest era of the Phanerozoic Eon, comprising the Lower Paleozoic (570–400 million years ago), containing the Cambrian, Ordovician, and Silurian periods; and the Upper Paleozoic (400–225 million years ago), containing the Devonian, Carboniferous (Mississippian and Pennsylvanian), and Permian periods.
Palermo
Palermo (pop. 696,700), capital, largest city, and major port of Sicily, Italy, on the northwestern coast.