/ Dictionary / Index M mutation: Meaning and Definition of Find definitions for: mu•ta•tion Pronunciation: (my-tā'shun), [key] — n. a sudden departure from the parent type in one or more heritable characteristics, caused by a change in a gene or a chromosome. an individual, species, or the like, resulting from such a departure. the act or process of changing. a change or alteration, as in form or nature. umlaut. (in Celtic languages) syntactically determined morphophonemic phenomena that affect initial sounds of words. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: mutation (Thesaurus) mutate mutatis mutandis* Related Content Daily Word Quiz: gregarious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language