Breadcrumb Home > Thesaurus > B Synonyms of benadryl Find synonyms for: Noun1. diphenhydramine, Benadryl, antihistamineusage: antihistamine (trade name Benadryl) used to treat allergic reactions involving the nasal passages (hay fever) and also to treat motion sicknessWordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved.Definition and meaning of benadryl (Dictionary) ✖ Related Content Daily Word Quiz: guilloche Analogy of the Day: Today’s Analogy Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language