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diphenhydramine Syllabification: di·phen·hy·dra·mine
Pronunciation: /ˌdīfenˈhīdrəmēn/

Definition of diphenhydramine in English:


An antihistamine compound used for the symptomatic relief of allergies.
  • A synthetic amine, usually used as a hydrochloride salt; chemical formula: C17H21NO
Example sentences
  • Take an antihistamine containing diphenhydramine (Benadryl, Tylenol Severe Allergy) or chlorpheniramine maleate (Chlor-Trimeton, Teldrin).
  • Amitriptyline, diazepam and diphenhydramine (in Tylenol PM) are considered risky for older individuals.
  • The sedating antihistamine diphenhydramine is found in Benadryl, Tylenol PM and Sominex.


1940s: from diphen- (denoting the presence of two phenyl groups) + hydr- + amine.

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