# biennial

> English word · Adjective · IPA /baɪˈɛn.i.əl/ · frequency rank #20,854

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

## Etymology
Borrowed from Latin bienni(um) (“two-year period”) [from bis, bi- (“twice”) + annus (“year”)] + -al (suffix forming adjectives). By surface analysis, bi- + -ennial.

## Easily confused with
- **biennale** (https://plainspell.com/en/vs/biennale-vs-biennial)

## Common misspellings (9)
`bbiennial`, `beinnial`, `bienial`, `bieninal`, `biennail`, `bienniall`, `biennila`, `binenial`, `ibennial`

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