# triennial

> English word · Adjective · IPA /tɹaɪˈɛniəl/ · frequency rank #53,921

## Definitions
1. Happening every three years.
2. Lasting for three years.

## Etymology
From Latin triennium (“three-year period”), from tres (“three”) + annus (“year”). By surface analysis, tri- + -ennial.

## Source
Compiled from Wiktionary via kaikki.org (CC BY-SA). Data vintage: 2026-05-06.
Canonical page: https://plainspell.com/en/word/triennial