Columbia Encyclopedia

Search results

500 results found

glacial periods

(Encyclopedia)glacial periods, times during which large portions of the earth's surface were covered with thick glacial ice sheets. In the Pleistocene epoch, in the Carboniferous and Permian periods of the Paleozoi...

erosion

(Encyclopedia)erosion ĭrōˈzhən [key], general term for the processes by which the surface of the earth is constantly being worn away. The principal agents are gravity, running water, near-shore waves, ice (most...

Hussein, Saddam

(Encyclopedia)Hussein, Saddam sädämˈ ho͞osānˈ [key], 1937–2006, Iraqi political leader. A member of the Ba'ath party, he fled Iraq after participating (1959) in an assassination attempt on the country's pri...

Ibsen, Henrik

(Encyclopedia)Ibsen, Henrik hĕnˈrĭk ĭbˈsən [key], 1828–1906, Norwegian dramatist and poet. His early years were lonely and miserable. Distressed by the consequences of his family's financial ruin and on his...

Hals, Frans

(Encyclopedia)Hals, Frans fräns häls [key], c.1580–1666, Dutch painter of portraits and genre scenes, b. Antwerp. Hals spent most of his life in Haarlem, where he studied with Karel van Mander and became (1610)...

Aral Sea

(Encyclopedia)Aral Sea ărˈəl [key], salt lake, SW Kazakhstan and NW Uzbekistan, E of the Caspian Sea in an area of interior drainage. To the north and west are the edges of the arid Ustyurt Plateau; the Kyzyl Ku...

Stowe, Harriet Beecher

(Encyclopedia)Stowe, Harriet Beecher, 1811–96, American novelist and humanitarian, b. Litchfield, Conn. With her novel Uncle Tom's Cabin, she stirred the conscience of Americans concerning slavery and thereby inf...

cocaine

(Encyclopedia)cocaine kōkānˈ, kōˈkān [key], alkaloid drug derived from the leaves of the coca shrub. A commonly abused illegal drug, cocaine has limited medical uses, most often in surgical applications that ...

drug addiction and drug abuse

(Encyclopedia)drug addiction and drug abuse, chronic or habitual use of any chemical substance to alter states of body or mind for other than medically warranted purposes. Traditional definitions of addiction, with...

occupational disease

(Encyclopedia)occupational disease, illness incurred because of the conditions or environment of employment. Unlike with accidents, some time usually elapses between exposure to the cause and development of symptom...