osmeterium

[oz-mi-teer-ee-uh m]

noun, plural os·me·te·ri·a [oz-mi-teer-ee-uh] /ˌɒz mɪˈtɪər i ə/.

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

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019