Word.ws English Dictionary

diphenhydramine

UK/ˌdʌɪ.fɛnˈhʌɪ.dɹəm.iːn//ˌdaɪˌfɛnˈhaɪ.dɹəˌmiːn/

diphenhydramine noun: an antihistamine and anticholinergic drug that blocks the effect of histamine at H₁ receptor sites, relieving allergy symptoms. It also reduces smooth muscle contraction, increases heart rate, and sedates the user by blocking muscarinic acetylcholine receptors (mAChRs).

diphenhydramine: an antihistamine and anticholinergic drug that blocks the effect of histamine at H₁ receptor sites,...
Image: Benrr101, CC BY 3.0, via Wikimedia Commons

Noun

diphenhydramine (countable and uncountable, plural diphenhydramines)

  1. An antihistamine and anticholinergic drug that blocks the effect of histamine at H₁ receptor sites, relieving allergy symptoms. It also reduces smooth muscle contraction, increases heart rate, and sedates the user by blocking muscarinic acetylcholine receptors (mAChRs).
    • Diphenhydramine is a convenient and cheap antihistamine for use, but there are other drugs that do not make the user tired.
    Synonyms:
    ZzzQuil, Benadryl

Synonyms of diphenhydramine

Forms of diphenhydramine

pluraldiphenhydramines

Origin of diphenhydramine

From diphen(yl) + (benz)hydr(yl) + -amine.

Questions about diphenhydramine

What does diphenhydramine mean?
Diphenhydramine means an antihistamine and anticholinergic drug that blocks the effect of histamine at H₁ receptor sites, relieving allergy symptoms. It also reduces smooth muscle contraction, increases heart rate, and sedates the user by blocking muscarinic acetylcholine receptors (mAChRs).
What part of speech is diphenhydramine?
Diphenhydramine is a noun.
How do you pronounce diphenhydramine?
Diphenhydramine is pronounced /ˌdʌɪ.fɛnˈhʌɪ.dɹəm.iːn/ (UK).
What is the plural of diphenhydramine?
The plural of diphenhydramine is diphenhydramines.

Words near diphenhydramine in the dictionary

  1. diphenadione
  2. diphenamid
  3. diphenan
  4. diphenanthrene
  5. diphencyprone
  6. diphenhydramine
  7. diphenhydramines
  8. diphenic
  9. diphenidine
  10. diphenidol
  11. diphenism

Source and license

Adapted from Wiktionary: diphenhydramine (page history and authors). Text available under the Creative Commons Attribution-ShareAlike 4.0 license. Word.ws reformatted the entry and added links. Wiktionary data of 2026-09-02.

Last updated:

Pronunciation audio from Wikimedia Commons, each file under its own free license: LL-Q1860 (eng)-Naomi Persephone Amethyst (NaomiAmethyst)-diphenhydramine.wav.

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