tropic: [14] The etymological notion underlying the word tropic is of ‘turning’, and the reason for its application to the hot regions of the world is that the two lines of latitude which bound them (the tropic of Cancer and the tropic of Capricorn) mark the points at which the sun reaches its zenith at the solstices and then ‘turns’ back. The word comes via Latin tropicus from Greek tropikós, a derivative of tropé ‘turning’ (source also of English trophy and related to the second syllable of contrive). => contrive, trophy, troubadour[tropic etymology, tropic origin, 英语词源]