from Wiktionary, Creative Commons Attribution/Share-Alike License
- proper n. A taxonomic superclass within the subphylum Vertebrata — the jawless fishes, or agnathans.
from the GNU version of the Collaborative International Dictionary of English
- n. a class of eel-shaped chordates with a cartilaginous skeleton lacking jaws, scales, and pelvic fins. Among these are the lampreys and hagfishes. There are some extinct forms.
from The Century Dictionary and Cyclopedia
- A section of geophilous gastropods destitute of jaws.
- A class of fishes, or fishlike vertebrates, characterized by the absence of jaws and shoulder-girdle. It contains the extinct ostracoderms and the existing lampreys.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. superclass of eel-shaped chordates lacking jaws and pelvic fins: lampreys; hagfishes; some extinct forms
From Ancient Greek ἀ- (a-, "without") + γνάθος (gnathos, "jaw"). (Wiktionary)