Cyclostomata

noun plural
Cy·​clo·​sto·​ma·​ta | \ ˌsī-klō-ˈstō-mət-ə How to pronounce Cyclostomata (audio) , ˌsik-lō- How to pronounce Cyclostomata (audio) , -ˈstäm-ət-ə\

Medical Definition of Cyclostomata

: a class or order of primitive vertebrates that have a large jawless sucking mouth, no limbs or paired fins, a wholly cartilaginous skeleton with persistent notochord, and 6 to 14 pairs of gill pouches and that include the lampreys and the hagfishes — compare chondrichthyes