gnatho-

Proto-Indo-European root, probably originally "jaw, jawbone," but also forming words for "chin, cheek." It forms all or part of: chin; Compsognathus; gnathic; gnatho-.

It is the hypothetical source of/evidence for its existence is provided by: Sanskrit hanuh "jaw," Avestan zanu- "chin;" Armenian cnawt "jawbone, cheek;" Lithuanian žándas "jawbone;" Greek genus "chin, lower jaw," geneion "chin;" Old Irish gin "mouth," Welsh gen "jawbone, chin;" Old English cin, "chin."

"having protruding jaws," 1836, from pro- + gnatho- "jaw" + -ous. Prognathic (1845) means the same. Related: Prognathism.