- the parallel of latitude 23°26ʹ north (tropic of Cancer) or south (tropic of Capricorn) of the equator.
- ASTRONOMYeach 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 region between the tropics of Cancer and Capricorn.plural noun: the tropics