/ Dictionary / Index D diphenhydramine: Meaning and Definition of Find definitions for: di•phen•hy•dra•mine Pronunciation: (dī"fen-hī'dru-mēn"), [key] — n. Pharm. a white, crystalline, antihistaminic compound, CHNO, used orally, topically, and parenterally, esp. for allergies. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: diphenhydramine (Thesaurus) diphenamid diphenoxylate Related Content Daily Word Quiz: arid Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language