pro·​sto·​mi·​um prō-ˈstō-mē-əm How to pronounce prostomium (audio)
plural prostomia prō-ˈstō-mē-ə How to pronounce prostomium (audio)
: the portion of the head of an annelid worm (such as an earthworm) that is situated in front of the mouth
prostomial adjective

Word History


New Latin, from Greek pro- + stoma mouth — more at stomach entry 1

First Known Use

1870, in the meaning defined above

Time Traveler
The first known use of prostomium was in 1870

Dictionary Entries Near prostomium

Cite this Entry

“Prostomium.” Dictionary, Merriam-Webster, Accessed 20 Apr. 2024.

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