thymine

/ˈθaɪmɪn/

//ˈθaɪmɪn// noun

"thymine" is a 7-letter English headword indexed on PlainSpell.

The verdict

“thymine” is uncommon English (frequency #94,337 among 27,828 “T” headwords), classed as a noun. The kind of spelling people second-guess.

#94,337
frequency rank, English
27,828
“T” headwords

According to Wiktionary data (CC BY-SA, analyzed May 6, 2026) - A heterocyclic base, 5-methylpyrimidine-2,4(1H,3H)-dione; it pairs with adenine in DNA.

Key facts for thymine
PropertyValue
Headwordthymine
LanguageEnglish
Part of speechNoun
IPA/ˈθaɪmɪn/
Letters7
Frequency rank#94,337
Misspellings tracked0
Confusable pairs0
SourceWiktionary (kaikki.org)

Where “thymine” sits in English frequency

Every-word frequency runs from the handful of words we use constantly (left) to the long tail used once in a blue moon (right). thymine lands here:

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

Scale is logarithmic (each tick is 10× rarer). Source: FrequencyWords open word-frequency list.

Rare enough to double-check

thymine is uncommon English at frequency #94,337 among 27,828 “T” headwords, classed as anoun, transcribed /ˈθaɪmɪn/. Rarity is why readers land here mid-draft. Gloss: "A heterocyclic base, 5-methylpyrimidine-2,4(1H,3H)-dione; it pairs with adenine in DNA.".

The misspelling generator found no plausible variants for thymine, and the word's spelling is regular enough that our generator found nothing worth flagging. No close-neighbour confusable shows up for this headword in our dataset, since its spelling is unusual enough that it doesn't cluster with a lookalike.

Etymologically, the entry records: From thymus + -ine. Thymine was first isolated in 1893 by Albrecht Kossel and Albert Neumann from calves' thymus glands, hence its name. The correct English form is thymine, spelled T-H-Y-M-I-N-E.

Definition

  1. 1
    A heterocyclic base, 5-methylpyrimidine-2,4(1H,3H)-dione; it pairs with adenine in DNA.

Etymology

From thymus + -ine. Thymine was first isolated in 1893 by Albrecht Kossel and Albert Neumann from calves' thymus glands, hence its name.

This word in other languages

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 "thymine"?
"thymine" is spelled T-H-Y-M-I-N-E. The IPA pronunciation is /ˈθaɪmɪn/.
What does "thymine" mean?
As a noun, "thymine" means: A heterocyclic base, 5-methylpyrimidine-2,4(1H,3H)-dione; it pairs with adenine in DNA.
How do you pronounce "thymine"?
The IPA (International Phonetic Alphabet) transcription for "thymine" is /ˈθaɪmɪn/. 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 "thymine"?
From thymus + -ine. Thymine was first isolated in 1893 by Albrecht Kossel and Albert Neumann from calves' thymus glands, hence its name. 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.

Using “thymine”

The practical upshot for anyone who landed here from a spell-check.

  • The one correct English spelling is T-H-Y-M-I-N-E - every other letter order is a misspelling in standard orthography.
  • Say it as /ˈθaɪmɪn/ (IPA); tap the speaker on the pronunciation badge to hear it where audio exists.
  • Browse more English words and confusable pairs in the same reference. English words

Other uncommon English words near this rank

Data Source

Wiktionary (via kaikki.org), licensed under CC BY-SA & GFDL. Word ordering uses an open word-frequency list; misspelling variants are generated by edit-distance from the correct headword.

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

Source: FrequencyWords open word-frequency list