biennial

adjective

bi·​en·​ni·​al (ˌ)bī-ˈe-nē-əl 

1

: occurring every two years

a biennial celebration

2

: continuing or lasting for two years

specifically, of a plant : growing vegetatively during the first year and fruiting and dying during the second

Biennial herbs flower in their second year.

biennial noun

biennially

(ˌ)bī-ˈe-nē-ə-lē 

adverb

What do bimonthly and biweekly mean?: Usage Guide

Many people are puzzled about bimonthly and biweekly, which are often ambiguous because they are formed from two different senses of bi-: "occurring every two" and "occurring two times." This ambiguity has been in existence for nearly a century and a half and cannot be eliminated by the dictionary. The chief difficulty is that many users of these words assume that others know exactly what they mean, and they do not bother to make their context clear. So if you need bimonthly or biweekly, you should leave some clues in your context to the sense of bi- you mean. And if you need the meaning "twice a," you can substitute semi- for bi-. Biannual and biennial are usually differentiated.

Did you know?

Biennial conventions, celebrations, competitions, and sports events come every two years. Biennials are plants that live two years, bearing flowers and fruit only in the second year. (Carrots and sugar beets are two examples; since we're only interested in their roots, we don't wait another year to see their flower and fruit.) In contrast, semiannual means "twice a year". But no one can agree whether biweekly means "twice a week" or "every two weeks", and whether bimonthly means "twice a month" or "every two months". Maybe we should stop using both of them until we can decide.

Examples of biennial in a Sentence

The governor explained the biennial budget proposal.

Recent Examples on the Web

The biennial multi-sport event started in 1959, and features around a dozen nations, but cricket has only been part of the programme in 2017 and last year in Phnom Penh, Cambodia. —Tristan Lavalette, Forbes, 25 Oct. 2024

The announcement, made during a visit to Pulaski High School outside of Green Bay, comes just two years after Gov. Tony Evers proposed $500 million in mental health services for the 2023-25 biennial budget. —Natalie Eilbert, Journal Sentinel, 24 Oct. 2024

With drivers balking at the high cost of owning electric vehicles, Stellantis NV, Renault SA and Volkswagen AG plan to showcase their latest budget EVs at the biennial event that starts Monday. —Jason Ma, Fortune Europe, 14 Oct. 2024

It is thought that the biennial industry showcase, which opened in Paris on Monday and runs through to Sunday, could prove to be a turning point for Europe’s auto industry. —Sam Meredith, CNBC, 17 Oct. 2024

Word History

First Known Use

1562, in the meaning defined at sense 1

Kids Definition

biennial

adjective

bi·​en·​ni·​al (ˈ)bī-ˈen-ē-əl 

1

: occurring every two years

2

: growing stalks and leaves one year and flowers and fruit the next before dying

biennial noun

biennially

-ē-ə-lē 

adverb