1) Having a projecting lower jaw 2) Having protrusive jaws 3) Hypognathous 4) Lantern-jawed 5) Prognathic 1) Hypognathous 2) Prognathic 
• (a.) Having the jaws projecting beyond the upper part of the face; -- opposed to orthognathous. See Gnathic index, under Gnathic.
Having a more or less horizontal head, with the mouth-parts at the front.
(prog´nә-thәs) having projecting jaws.
Prog'na·thous adjective [ Greek ... before + ... the jaw] (Anat.) Having the jaws projecting beyond the upper part of the face; -- opposed to orthognathous . See Gnathic index , under Gnathic . « Their countenances had the true prognathous character.» 
Having a more or less horizontal head, with the mouth-parts at the front.
Type: Term Pronunciation: prog′nă-thŭs Synonyms: prognathic
[adj] - having a projecting lower jaw
prognathic adjective having a projecting lower jaw
mouthparts are directed forwards from the head from the insect's normal position
having protrusive jaws; having a gnathic index over 103.