prostomium

[proh-stoh-mee-uh m]

noun, plural pro·sto·mi·a [proh-stoh-mee-uh] /proʊˈstoʊ mi ə/.

the unsegmented, preoral portion of the head of certain lower invertebrates.

Origin of prostomium

1865–70; < New Latin < Greek prostómion mouth. See pro-², stoma, -ium

Related formspro·sto·mi·al, adjective

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

Examples from the Web for prostomium

Historical Examples of prostomium

Prostomium: The region in front of the mouth; the preoral part of the head.
The Sea-beach at Ebb-tide
Augusta Foote Arnold
Prostomium wider than long, deeply bilobed, the median tentacle inserted deeply in the intervening incision.
Journal of Entomology and Zoology, Vol. 11. No. 1.
Various
Prostomium shortly subcordate, well rounded in front, incurved caudally.
Journal of Entomology and Zoology, Vol. 11. No. 1.
Various
Prostomium of usual general form; consisting of fourteen or fifteen rings.
Journal of Entomology and Zoology, Vol. 11. No. 1.
Various
Prostomium with a lateral process or horn on each side in front, notched in front at middle.
Journal of Entomology and Zoology, Vol. 11. No. 1.
Various

British Dictionary definitions for prostomium

prostomium

noun plural -mia (-mɪə)

the lobe at the head end of earthworms and other annelids: bears tentacles, palps, etc, or forms part of a sucker or proboscis

Derived Formsprostomial, adjective

Word Origin for prostomium

via New Latin from Greek prostomion mouth

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for prostomium

1870, Latinized form of Greek prostomion "fore-mouth, something before the mouth," from pro "before" (see pro-) + stoma "mouth" (see stoma).