/ Dictionary / Index R regressive assimilation: Meaning and Definition of Find definitions for: regres'sive assimila'tion Pronunciation: [key] — Phonet. Phonet. assimilation in which a following sound has an effect on a preceding one, as in pronouncing have in have to as (haf&hasp;), influenced by the voiceless (t) in to. Also calledCf. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. regressive regret Related Content Daily Word Quiz: vertigo Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language