n. The orientation, locomotion, or migration of a cell or of an organism in relation to an external substance or form of energy.n. In surgery, an operation by which parts which have quitted their natural situation are replaced by manipulation, as in reducing hernia, etc.n. In ancient architecture, that disposition which assigns to every part of a building its just dimensions. It is synonymous with ordonnance in modern architecture.n. In Greek antiquity, a division of troops corresponding more or less closely to the modern battalion; also, a larger division of an army, as a regiment or a brigade.n. In zoology, classification; taxonomy; taxology.n. In grammar and rhetoric, arrangement; order.