osmeterium

[ oz-mi-teer-ee-uhm ]

noun

, plural os·me·te·ri·a [oz-mi-, teer, -ee-, uh].

1. a glandular process on the first thoracic segment of many caterpillars that emits a noxious odor to ward off predators.

Word History and Origins

Origin of osmeterium¹

First recorded in 1815–20; from New Latin osmētērium, from Greek osmḗ “odor, smell” + -tērion noun suffix for places and utensils, akin to Latin -tōrium; see -tory ²( def )