any of a family (Petromyzontidae) of eel-shaped freshwater or anadromous jawless fishes that include those cyclostomes having well-developed eyes and a large disk-shaped suctorial mouth armed with horny teeth —called also lamprey eel
lamprey
noun(lam-prey)
a large anadromous lamprey (Petromyzon marinus) that has a mottled upper surface, is an ectoparasite of fish, and is sometimes used as food