/ Dictionary / Index M mesognathous: Meaning and Definition of Find definitions for: me•sog•na•thous Pronunciation: (mi-zog'nu-thus, -sog'-), [key] — adj. Anthropol. having medium, slightly protruding jaws. having a moderate or intermediate gnathic index of from 98 to 103. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. mesoglea mesolecithal Related Content Daily Word Quiz: eureka Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language