Any of various fishes lacking jaws, including the hagfishes and the lampreys and many extinct groups, such as the ostracoderms.
Origin of agnathana- 1Greek gnathos jaw ; see genu-2 in Indo-European roots. -an 1
(comparative more agnathan, superlative most agnathan)
From Agnatha, from Ancient Greek á¼€- (a-, “without") + Î³Î½Î¬Î¸Î¿Ï‚ (gnathos, “jaw")