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pruning

(Encyclopedia)pruning, the horticultural practice of cutting away an unwanted, unnecessary, or undesirable plant part, used most often on trees, shrubs, hedges, and woody vines. Man uses pruning to remove diseased ...

optometry

(Encyclopedia)optometry ŏptŏmˈətrē [key], eye-care specialty concerned with eye examination, determination of visual abilities, diagnosis of eye diseases and conditions, and the prescription of lenses and othe...

Jakobson, Roman

(Encyclopedia)Jakobson, Roman rəmänˈ yäkˈôbsən [key], 1896–1982, Russian-American linguist and literary critic, b. Moscow. He coined the term structural linguistics and stressed that the aim of historical ...

harvester

(Encyclopedia)harvester, farm machine that mechanically harvests a crop. Small-grain harvesting has been mechanized to a certain extent since early times. In the modern period the first harvester to gain general ac...

perversion, sexual

(Encyclopedia)perversion, sexual, in psychology, sexual behavior deemed pathological by its deviation from “normal” sexual desire. The definition of sexual perversion has shifted considerably over time: indeed,...

photography, still

(Encyclopedia)photography, still, science and art of making permanent images on light-sensitive materials. See also photographic processing; motion picture photography; motion pictures. By the end of ...

nettle

(Encyclopedia)nettle, common name for the Urticaceae, a family of fibrous herbs, small shrubs, and trees found chiefly in the tropics and subtropics. Several genera of nettles are covered with small stinging hairs ...

Mazepa, Ivan

(Encyclopedia)Mazepa, Ivan ēvänˈ məzyāˈpə [key], c.1640–1709, Cossack hetman [leader] in the Russian Ukraine. He was made hetman (1687) on the insistence of Prince Gallitzin, adviser to the Russian regent,...

monkeypox

(Encyclopedia)monkeypox, rare disease caused by infection with the monkeypox virus, which is related to the viruses that cause smallpox and cowpox. The symptoms of monkeypox, which typically take 1 to 2 weeks to ap...

Magna Graecia

(Encyclopedia)Magna Graecia măgˈnə grēˈshə [key] [Lat.,=great Greece], Greek colonies of S Italy. The Greek overseas expansion of the 8th cent. b.c. founded a number of towns that became the centers of a new,...