noun
also os·ma·te·ri·um ˌäzməˈtirēəm
( plural osmete·ria also osmate·ria -ēə)
Etymology: New Latin, irregular from Greek osmē odor
: a protrusile forked process that emits a disagreeable odor, is borne on the first thoracic segment of the larvae of many butterflies of the family Papilionidae, and is probably a defensive organ