Definitions

1. adjective

Pertaining to or characterized by a mouth or opening that is not a true mouth, especially in certain invertebrates such as leeches and hagfish.

“The cyclostomous leeches were a fascinating subject for the marine biologist to study.”

2. noun

A leech or hagfish, especially one of the class Agnatha, which has a mouth that is not a true mouth.

“The cyclostomous in the aquarium were feeding on the blood of the fish.”

3. noun

A type of primitive vertebrate with a jawless mouth.

“Cyclostomous fish were among the first vertebrates to inhabit the planet.”