/ Dictionary / Index R retrogression: Meaning and Definition of Find definitions for: ret•ro•gres•sion Pronunciation: (re"tru-gresh'un), [key] — n. the act of retrogressing; movement backward. degeneration; retrograde metamorphosis; passing from a more complex to a simpler structure. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: retrogression (Thesaurus) retrogress retrogressive Related Content Daily Word Quiz: clairvoyant Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language