Columbia Encyclopedia

Search results

500 results found

marriage

(Encyclopedia)marriage, socially sanctioned union that reproduces the family. In all societies the choice of partners is generally guided by rules of exogamy (the obligation to marry outside a group); some societie...

malaria

(Encyclopedia)malaria, infectious parasitic disease that can be either acute or chronic and is frequently recurrent. Malaria is common in Africa, Central and South America, the Mediterranean countries, Asia, and ma...

Nature Conservancy

(Encyclopedia)Nature Conservancy, nonprofit organization established in 1951 to preserve or aid in the preservation of natural environments. It protects wilderness areas in the United States and Canada and is affil...

Folsom culture

(Encyclopedia)Folsom culture fŏlˈsəm, fŭlˈ– [key], a group of Paleo-Indians (see Americas, antiquity and prehistory of the) known through artifacts first excavated (1926) near Folsom, E of Raton, N.Mex. The ...

nitrocellulose

(Encyclopedia)nitrocellulose, nitric acid ester of cellulose (a glucose polymer). It is usually formed by the action of a mixture of nitric and sulfuric acids on purified cotton or wood pulp. The extent of nitratio...

Klein, Christian Felix

(Encyclopedia)Klein, Christian Felix klīn [key], 1849–1925, German mathematician. He is noted for his work in geometry and on the theory of functions. His Erlangen program (1872) for unifying the diverse forms ...

picketing

(Encyclopedia)picketing, act of patrolling a place of work affected by a strike in order to discourage its patronage, to make public the workers' grievances, and in some cases to prevent strikebreakers from taking ...

Antifa

(Encyclopedia)Antifa, American political movement, is a loose coalition of progressive voices opposing the rise of homophobic, authoritarian, xenophobic, and racist movements worldwide. Inspired by the ...

Triad Society

(Encyclopedia)Triad Society, name given to a number of Chinese antidynastic secret societies by 19th-century Western observers. Most of these groups claimed descent from the Heaven and Earth Society (Taendi hui) or...

AIDS, in medicine

(Encyclopedia)AIDS or acquired immunodeficiency syndrome, fatal disease caused by a rapidly mutating retrovirus that attacks the immune system and leaves the victim vulnerable to infections, malignancies, and neuro...