Biennial

How to spell biennial

8 letters · 4 syllables

How to pronounce biennial

Say the part in capitals loudest.

What does biennial mean?

1. adjectiveHappening once every two years.
2. nounA plant that takes two growing seasons to complete its life cycle, flowering in the second year.

Biennial in a sentence

• adjective

  The committee holds its biennial review in odd-numbered years only.

• noun

  Foxglove is a classic biennial that grows leaves one year and flowers the next.

• adjective

  The city funds the festival on a biennial basis, so it returns every second summer.

• noun

  She sowed the biennial in autumn so it would bloom the following summer.

Where does biennial come from?

Language of origin: Latin

This word comes straight from the Latin biennium, the term Romans used for a span of two years, which was built from bi- meaning 'two' and annus meaning 'year'. When annus combined with a prefix, its vowel shifted and the spelling became -enn-, which is exactly why we write biennial with a double n rather than the single n of 'annual'. English adopted it in the early 1600s, first to describe anything happening once every two years and later, in gardening, to label a plant that needs two growing seasons to complete its life. The very same annus root sits inside familiar words like 'annual', 'anniversary' and 'perennial', so recognising that family helps fix the spelling. The persistent trap is the close cousin 'biannual', which confusingly means twice a year, the near opposite of biennial.

How the word is built

• bi- (two)
• -enn- (from Latin annus: year)
• -ial (adjective/noun suffix)