diphenhydramine

/ˌdʌɪ.fɛnˈhʌɪ.dɹəm.iːn/

//ˌdʌɪ.fɛnˈhʌɪ.dɹəm.iːn// noun

By · According to Wiktionary data (CC BY-SA) ·

"diphenhydramine" is a 15-letter English headword indexed on PlainSpell.

The verdict

“diphenhydramine” is uncommon English (frequency #88,276 among 3,470 “D” headwords), classed as a noun. The kind of spelling people second-guess.

#88,276
frequency rank, English
3,470
“D” headwords

According to Wiktionary data (CC BY-SA, analyzed September 3, 2026) - 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 ...

Corpus desk

Index EN-diphenhydramine · diphenhydramine · English

diphenhydramine · rank #88,276 · 0 variants · 0 confusables

  • FREQ-RARE #88,276
  • LEN-MEGA 15 letters
  • VOW-6 6 vowels
  • CONFUS-0 No pairs
  • VAR-0 0 variants
  • BOOK-MID 3,470
  • PHOTO-FINISH Dilworth

Nearest frequency peer: Dilworth (-2 rank slots)

Read with this headword: Spelling guide for this pattern

Desk codes from Wiktionary headword shape, FrequencyWords rank tier, confusable-pair count, generated misspelling depth, letter-cohort book size, and photo-finish peer. Not a difficulty grade.

Long-tail ranks near “diphenhydramine”

Sparse band: bars invert rank so rarer forms read shorter

corpus weight

What this shows Long-tail view: where “diphenhydramine” sits against similarly uncommon English ranks.

Source FrequencyWords open word-frequency list As of September 3, 2026
Key facts for diphenhydramine
PropertyValue
Headworddiphenhydramine
LanguageEnglish
Part of speechNoun
IPA/ˌdʌɪ.fɛnˈhʌɪ.dɹəm.iːn/
Letters15
Frequency rank#88,276
Misspellings tracked0
Confusable pairs0
SourceWiktionary (kaikki.org)

Long-tail rank of “diphenhydramine” in English

Word frequency stretches from the small set of words we reach for constantly (left) out to the long tail barely used once in a while (right).diphenhydraminefalls in this rarity band:

#1#100#1K#10K#100K
← used constantlyrarely used →

The axis is logarithmic, with each marked tick roughly ten times rarer than the last. Rare peers in the same band: “Dilworth” (#88,274), “dieback” (#88,272), “discolouration” (#88,280). Among 3,470 “D” headwords, “diphenhydramine” is #88,276. Source: FrequencyWords open word-frequency list.

Rare enough to double-check

diphenhydramine is uncommon English at frequency #88,276 among 3,470 “D” headwords, classed as anoun, transcribed /ˌdʌɪ.fɛnˈhʌɪ.dɹəm.iːn/. Rarity is why readers land here mid-draft. Gloss: "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 ...".

We couldn't generate a plausible misspelling set for diphenhydramine, since its letter pattern doesn't lend itself to common typo substitutions. This entry stands alone in our confusable dataset, which typically means the spelling is too distinctive to be mistaken for another word.

Etymologically, the entry records: From diphen(yl) + (benz)hydr(yl) + -amine. The correct English form is diphenhydramine, spelled D-I-P-H-E-N-H-Y-D-R-A-M-I-N-E.

Definition

  1. 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).

Recorded use

Wiktionary example

These source excerpts show how diphenhydramine appears in context. They illustrate usage; the definition above remains the entry’s reference meaning.

  1. Diphenhydramine is a convenient and cheap antihistamine for use, but there are other drugs that do not make the user tired.

Etymology

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

Definitions, pronunciation, and etymology for this entry are drawn from Wiktionary via the kaikki.org structured extract (CC BY-SA); frequency ordering uses the FrequencyWords open word-frequency list (2018 English corpus, MIT). See the methodology for how each field is sourced and updated.

Frequently Asked Questions

How do you spell "diphenhydramine"?
"diphenhydramine" is spelled D-I-P-H-E-N-H-Y-D-R-A-M-I-N-E. The IPA pronunciation is /ˌdʌɪ.fɛnˈhʌɪ.dɹəm.iːn/.
What does "diphenhydramine" mean?
As a noun, "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 ...
How do you pronounce "diphenhydramine"?
The IPA (International Phonetic Alphabet) transcription for "diphenhydramine" is /ˌdʌɪ.fɛnˈhʌɪ.dɹəm.iːn/. Click the speaker icon on the pronunciation badge above to hear it spoken aloud where audio is available.
What is the origin of the word "diphenhydramine"?
From diphen(yl) + (benz)hydr(yl) + -amine. See the full etymology section above for more details.
Is PlainSpell free to use?
Yes, PlainSpell is a completely free word reference. You can look up definitions, pronunciations, confusable pairs, homophones, and spelling corrections across 5 languages without any sign-up or subscription.

Similar English words by spelling shape

Same letter count and similar misspelling depth for "diphenhydramine", not the corpus desk frequency band.

Same letter count

Frequency-ranked English headwords with 15 letters (nearest by frequency rank).

destructiveness#88,267countercultural#88,232gluconeogenesis#88,386anticompetitive#88,056

Source: Wiktionary (via kaikki.org) Structured Wiktionary extract

Source: FrequencyWords open word-frequency list