/ Dictionary / Index D diluent: Meaning and Definition of Find definitions for: dil•u•ent Pronunciation: (dil'y-unt), [key] — adj. serving to dilute; diluting. —n. a diluting substance. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: diluent (Thesaurus) diltiazem dilute Related Content Daily Word Quiz: careening Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language