-tropin

Etymology tree Proto-Indo-European *trep-der. Ancient Greek τρέπω (trépō) Proto-Indo-European *-h₂ Proto-Indo-European *-éh₂ Ancient Greek -ᾱ (-ā) Ancient Greek -η (-ē) Ancient Greek τροπή (tropḗ) Proto-Indo-European *-kos Ancient Greek -κός (-kós) Ancient Greek -ικός (-ikós) Ancient Greek τροπῐκός (tropĭkós)bor. English -tropic Proto-Indo-European *-nós Proto-Indo-European *-iHnos Proto-Italic *-īnos Latin -īnusder. Old French -inbor. Middle English -in English -ineclip. English -in English -tropin From -tropic (“attracted to or acting upon”) + -in.

来源：wiktionary