n., pl., -la (-lə), or -lums.
A lid or flap covering an aperture, such as the gill cover in some fishes or the horny shell cover in snails or other mollusks.
[Latin, lid, from operīre, to cover.]
opercular o·per'cu·lar (-lər) adj.opercularly o·per'cu·lar·ly adv.
The American Heritage® Dictionary of the English Language, Fourth Edition Copyright © 2007, 2000 by Houghton Mifflin Company. Updated in 2009. Published by Houghton Mifflin Company. All rights reserved.
