- belonging or pertaining to the Cyclostomata, a subclass of jawless, eellike, marine vertebrates of the class Agnatha, comprising the lampreys and hagfishes.
- having a circular mouth.
- a cyclostome vertebrate; a lamprey or hagfish.
- any primitive aquatic jawless vertebrate of the class Cyclostomata, such as the lamprey and hagfish, having a round sucking mouth and pouchlike gills
- of, relating to, or belonging to the class Cyclostomata
