- Botany, Zoology. a part or organ serving as a lid or cover, as a covering flap on a seed vessel.
- the gill cover of fishes and amphibians.
- (in many gastropods) a horny plate that closes the opening of the shell when the animal is retracted.
Origin of operculum
1705–15; < New Latin, Latin: lid, cover, equivalent to oper(īre) to cover + -culum -cule2
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
Examples from the Web for opercula
It should be mentioned that the Serpulacea are provided with opercula.A Conchological Manual
George Brettingham Sowerby
The figures represent some of the commoner types of opercula.
These are the drum-covers or opercula, from beneath which the sound issues.An Introduction to Entomology: Vol. II (of 4)
It was shaped and ornamentally carved and painted to represent a wood-worm and inlaid along the rounded upper edge with opercula.The Whale House of the Chilkat
George T. Emmons
The opercula vary to a great extent in the different genera; in some cases they are calcareous, in others cartilaginous.
- the hard bony flap covering the gill slits in fishes
- the bony plate in certain gastropods covering the opening of the shell when the body is withdrawn
- botany the covering of the spore-bearing capsule of a moss
- biology any other covering or lid in various organisms
C18: via New Latin from Latin: lid, from operīre to cover
Word Origin and History for opercula
1713, from Latin operculum "cover, lid," from operire "to cover, close" (see weir), with instrumental suffix *-tlom. Related: Opercular.
Online Etymology Dictionary, © 2010 Douglas Harper
- Something resembling a lid or cover.
- The portions of the frontal, parietal, and temporal lobes covering the insula.
- The mucus sealing the endocervical canal of the uterus after conception.
- The attached flap in cases of torn retinal detachment.
- The mucosal flap partially or completely covering an unerupted tooth.
- A lid or flap covering an opening, such as the gill cover in some fish or the horny flap covering the opening of a snail.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.