/ Dictionary / Index A authigenic: Meaning and Definition of Find definitions for: au•thi•gen•ic Pronunciation: (ô"thi-jen'ik), [key] — adj. Geol. (of a constituent of a rock) formed in the rock where it is found. Cf. allogenic (def. 1). Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. authenticity author Related Content Daily Word Quiz: perspicacious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language