Tropin

Part of speech: noun

Definitions

1. A hormone or substance that acts to stimulate the activity of an organ or tissue
2. a chemical agent that promotes growth or function in a specific area of the body
3. a factor that influences physiological processes in a targeted manner

Etymology: "Tropin" is a modern scientific coinage, built from "tropic" with the chemical suffix "-in." The "tropic" part goes back to the Greek "tropikos," relating to a turning or change, which is also the root of the word "trope." The term describes substances that act on a specific target in the body, turning a physiological process one way or another, and the name reflects that sense of directed change. The suffix has a longer ancestry than the word itself. It descends from Latin "-inus," which passed through Old French "-in" into Middle English, where it was used to form adjectives and nouns. In chemistry it became a standard way to name substances, so that a compound could be labelled with a root and an "-in" ending to signal that it belonged to a family of such materials. Because "tropin" is a formation from existing English elements rather than an old inherited word, its meaning is fixed by its construction: a thing associated with "tropic" action, the directed influence described above.