Dictionary
tropo-
a combining form meaning “turn,” “reaction, response,” “change,” “troposphere,” used in the formation of compound words:
tropophilous. Also, esp. before a vowel,trop-.Cf.
-trope, -tropism, -tropy, -tropic, -tropous. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.