triennial
/tɹaɪˈɛniəl/
"triennial" is a 9-letter English headword indexed on PlainSpell.
The verdict
“triennial” is uncommon English (frequency #53,921 among 27,828 “T” headwords), classed as an adjective. The kind of spelling people second-guess.
- #53,921
- frequency rank, English
- 27,828
- “T” headwords
According to Wiktionary data (CC BY-SA, analyzed May 6, 2026) - Happening every three years.
| Property | Value |
|---|---|
| Headword | triennial |
| Language | English |
| Part of speech | Adjective |
| IPA | /tɹaɪˈɛniəl/ |
| Letters | 9 |
| Frequency rank | #53,921 |
| Misspellings tracked | 0 |
| Confusable pairs | 0 |
| Source | Wiktionary (kaikki.org) |
Where “triennial” sits in English frequency
Rare enough to double-check
triennial is uncommon English at frequency #53,921 among 27,828 “T” headwords, classed as anadjective, transcribed /tɹaɪˈɛniəl/. Rarity is why readers land here mid-draft. 2 senses are on record.
Zero misspellings are on record for triennial in our index, typically a sign the spelling maps closely to how the word sounds. It is not paired with a close-neighbour confusable in our dataset, which typically means the spelling is too distinctive to be mistaken for another word.
Etymologically, the entry records: From Latin triennium (“three-year period”), from tres (“three”) + annus (“year”). By surface analysis, tri- + -ennial. The correct English form is triennial, spelled T-R-I-E-N-N-I-A-L.
Definition
- 1Happening every three years.
- 2Lasting for three years.
Etymology
From Latin triennium (“three-year period”), from tres (“three”) + annus (“year”). By surface analysis, tri- + -ennial.
Synonyms
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
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Using “triennial”
The practical upshot for anyone who landed here from a spell-check.
- The one correct English spelling is T-R-I-E-N-N-I-A-L - every other letter order is a misspelling in standard orthography.
- Say it as /tɹaɪˈɛniəl/ (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.