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albino

(Encyclopedia)albino ălbīˈnō [key] [Port.,=white], animal or plant lacking normal pigmentation. The absence of pigment is observed in the body covering (skin, hair, and feathers) and in the iris of the eye. The...

chelating agents

(Encyclopedia)chelating agents kēˈlātĭng [key]. Certain organic compounds are capable of forming coordinate bonds (see chemical bond) with metals through two or more atoms of the organic compound; such organic ...

Addison's disease

(Encyclopedia)Addison's disease [for Thomas Addison], progressive disease brought about by atrophy of the outer layer, or cortex, of the adrenal gland; it is also called chronic adrenocortical insufficiency. The de...

valve

(Encyclopedia)valve, device for controlling the flow of fluids (liquids and gases). Valves vary in construction and size depending upon their function. Some are classified according to their method of operation or ...

Pretorius, Andries Wilhelmus Jacobus

(Encyclopedia)Pretorius, Andries Wilhelmus Jacobus prĭtôrˈēəs, Du. änˈdrēs vĭlhĕlˈməs yäkōˈbəs prātôrˈēəs [key], 1799–1853, Boer (Afrikaner) leader. He was elected (1838) commandant general o...

Ogilvy, David Mackenzie

(Encyclopedia)Ogilvy, David Mackenzie, 1911–99, British-American advertising executive. He was a chef in Paris and a door-to-door salesman before entering advertising, becoming an account executive in Britain and...

hero, in Greek religion

(Encyclopedia)hero, in Greek religion, famous person, who after his death, was worshiped as quasi-divine. The heroes might be actual great men and women, real or imaginary ancestors, or “faded” gods and goddess...

horned lizard

(Encyclopedia)horned lizard or horned toad, broad, flat-bodied lizards of the genus Phrynosoma, found in arid regions from extreme SW Canada to Guatemala. There are several species in the United States W of the Mis...

hypertrophy

(Encyclopedia)hypertrophy hīpûrˈtrəfē [key], enlargement of a tissue or organ of the body resulting from an increase in the size of its cells. Such growth accompanies an increase in the functioning of the tiss...

eclampsia

(Encyclopedia)eclampsia ĭklămpˈsēə [key], term applied to toxic complications that can occur late in pregnancy. Toxemia of pregnancy occurs in 10% to 20% of pregnant women; symptoms include headache, vertigo, ...