The Collaborative International Dictionary
Gnathic \Gnath"ic\, a. [Gr. gna`qos the jaw.] (Anat.) Of or pertaining to the jaw.
Gnathic index, in a skull, the ratio of the distance from the middle of the nasofrontal suture to the basion (taken equal to 100), to the distance from the basion to the middle of the front edge of the upper jaw; -- called also alveolar index.
Skulls with the gnathic index below 98 are
orthognathous, from 98 to 103 mesognathous, and
above 103 are prognathous.
--Flower.
Douglas Harper's Etymology Dictionary
"pertaining to the jaw," 1882, from Greek gnathos "jaw, cheek," properly "the lower jaw," cognate with Lithuanian žandas "jaw."
Wiktionary
a. Of or pertaining to the jaw.
Usage examples of "gnathic".
He wouldn't have been greatly surprised if he had glanced at his rearview mirror and seen Thomas Vanadium's blue Studebaker Lark Regal closely tailing him, not the real car raised from Quarry Lake, but a ghostly version, with the filthy-scabby-monkey spirit of the cop at the wheel, an ectoplasmic Naomi at his side, Victoria Bressler and Ichabod and Bartholomew Prosser and Neddy Gnathic in the backseat: the Studebaker packed full of spirits like a bozo-stuffed clown car in a circus, though there would be nothing funny about these revenge-minded spooks when the doors flew open and they came tumbling out.