tretinoin

/tɹəˈtɪn.əʊ.ɪn/

//tɹəˈtɪn.əʊ.ɪn// noun

"tretinoin" is a 9-letter English headword indexed on PlainSpell.

The verdict

“tretinoin” is uncommon English (frequency #82,867 among 3,151 “T” headwords), classed as a noun. The kind of spelling people second-guess.

#82,867
frequency rank, English
3,151
“T” headwords

According to Wiktionary data (CC BY-SA, analyzed September 3, 2026) - The all-trans isomer of retinoic acid that is applied to the skin to treat severe acne and reduce facial wrinkles, roughness, and pigmented spots.

Corpus desk

Index EN-tretinoin · tretinoin · English

tretinoin · rank #82,867 · 0 variants · 0 confusables

  • FREQ-RARE #82,867
  • LEN-LONG 9 letters
  • VOW-4 4 vowels
  • CONFUS-0 No pairs
  • VAR-0 0 variants
  • BOOK-MID 3,151
  • PHOTO-FINISH tricyclic

Nearest frequency peer: tricyclic (+1 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 “tretinoin”

Sparse band: bars invert rank so rarer forms read shorter

corpus weight

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

Source FrequencyWords open word-frequency list As of September 3, 2026
Key facts for tretinoin
PropertyValue
Headwordtretinoin
LanguageEnglish
Part of speechNoun
IPA/tɹəˈtɪn.əʊ.ɪn/
Letters9
Frequency rank#82,867
Misspellings tracked0
Confusable pairs0
SourceWiktionary (kaikki.org)

Long-tail rank of “tretinoin” 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).tretinoinfalls in this rarity band:

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

Ticks step logarithmically, so each one marks a roughly tenfold drop in how often the word turns up. Rare peers in the same band: “tricyclic” (#82,868), “transposing” (#82,865), “triforce” (#82,869). Among 3,151 “T” headwords, “tretinoin” is #82,867. Source: FrequencyWords open word-frequency list.

Rare enough to double-check

tretinoin is uncommon English at frequency #82,867 among 3,151 “T” headwords, classed as anoun, transcribed /tɹəˈtɪn.əʊ.ɪn/. Rarity is why readers land here mid-draft. Gloss: "The all-trans isomer of retinoic acid that is applied to the skin to treat severe acne and reduce facial wrinkles, roughness, and pigmented spots.".

We couldn't generate a plausible misspelling set for tretinoin, which points to an orthography that plays by predictable English rules. It is not paired with a close-neighbour confusable in our dataset, a sign it's visually distinctive enough not to be mixed up with another word.

Etymologically, the entry records: From tr(ans)- + retino(ic acid) + -in. The correct English form is tretinoin, spelled T-R-E-T-I-N-O-I-N.

Definition

  1. 1
    The all-trans isomer of retinoic acid that is applied to the skin to treat severe acne and reduce facial wrinkles, roughness, and pigmented spots.

Etymology

From tr(ans)- + retino(ic acid) + -in.

Synonyms

all-trans retinoic acidATRAtret

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 "tretinoin"?
"tretinoin" is spelled T-R-E-T-I-N-O-I-N. The IPA pronunciation is /tɹəˈtɪn.əʊ.ɪn/.
What does "tretinoin" mean?
As a noun, "tretinoin" means: The all-trans isomer of retinoic acid that is applied to the skin to treat severe acne and reduce facial wrinkles, roughness, and pigmented spots.
How do you pronounce "tretinoin"?
The IPA (International Phonetic Alphabet) transcription for "tretinoin" is /tɹəˈtɪn.əʊ.ɪn/. 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 "tretinoin"?
From tr(ans)- + retino(ic acid) + -in. 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 "tretinoin", not the corpus desk frequency band.

Same letter count

Frequency-ranked English headwords with 9 letters (nearest by frequency rank).

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

Source: FrequencyWords open word-frequency list