opercular bones

plural noun

: the bony plates developed in and supporting the gill cover in most fishes and being usually the opercle, preopercle, subopercle, and interopercle

The Ultimate Dictionary Awaits

Expand your vocabulary and dive deeper into language with Merriam-Webster Unabridged.

1. Expanded definitions
2. Detailed etymologies
3. Advanced search tools
4. All ad-free

Discover what makes Merriam-Webster Unabridged the essential choice for true word lovers.

Start Your Free Trial Now