From Merriam Webster dictionary:
- Main Entry:
- -tropic
- Function:
- adjective combining form
- Etymology:
- French -tropique, from Greek -tropos -tropous
1 : turning, changing, or tending to turn or change in a (specified) manner or in response to a (specified) stimulus <geotropic>
2 : attracted to or acting upon (something specified) <neurotropic>

