/ Dictionary / Index M mutagen: Meaning and Definition of Find definitions for: mu•ta•gen Pronunciation: (my'tu-jun, -jen"), [key] — n. a substance or preparation capable of inducing mutation. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: mutagen (Thesaurus) mutable sign mutagenesis Related Content Daily Word Quiz: panacea Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language