Definitions

1. noun

A bony or cartilaginous projection on the operculum of a fish, above and behind the gill openings.

“The preopercle of the fish was a distinctive feature that helped identify the species.”

2. noun

In some contexts, the preopercle refers to the preopercular bone in the skull of other animals, such as birds.

“The preopercle of the bird played a crucial role in its ability to fly.”