Pronunciation: (trop'ik),[key] —n. 1. Geog. a. either of two corresponding parallels of latitude on the terrestrial globe, one (tropic of Cancer) about 23½° N, and the other (tropic of Capricorn) about 23½° S of the equator, being the boundaries of the Torrid Zone. See diag. under zone. b. the tropics,the regions lying between and near these parallels of latitude; the Torrid Zone and neighboring regions.
2. Astron.either of two circles on the celestial sphere, one lying in the same plane as the tropic of Cancer, the other in the same plane as the tropic of Capricorn.
—adj. of, pertaining to, characteristic of, or occurring in the tropics; tropical: romance under the tropic skies of Old Mexico.
a combining form with the meanings “turned toward, with an orientation toward” that specified by the initial element (geotropic), “having an affinity for, affecting” what is specified (lipotropic; neurotropic; psychotropic), “affecting the activity of, maintaining” a specified organ (gonadotropic). Cf. -trophic.