Definition of opisthognathous in US English:

opisthognathous

adjective

Zoology
  • (of an animal) having retreating or backward-pointing jaws, teeth, or mandibles.

    • ‘Here the head is opisthognathous with the labium short and fused to the thorax.’

Origin

Mid 19th century: from opistho- + Greek gnathos ‘jaw’ + -ous.

Pronunciation

opisthognathous

/ˌäpəsˈTHäɡnəTHəs/