trop·ic1 / ˈträpik/ • n. the parallel of latitude 23°26′ north (tropic of Cancer) or south (tropic of Capricorn) of the equator. ∎ Astron. each of two corresponding circles on the celestial sphere where the sun appears to turn after reaching its greatest declination, marking the northern and southern limits of the ecliptic. ∎ (the tropics) the region between the tropics of Cancer and Capricorn.• adj. another term for tropical (sense 1).trop·ic2 • adj. 1. Biol. relating to, consisting of, or exhibiting tropism. 2. Physiol. variant spelling of trophic.
1. pert. to the ‘turning’ of the sun at the solstice,
2. fig., f. tropē turning; see prec., -IC.
So tropical pert. to a tropic XVI (of the torrid zone XVII); metaphorical XVI.