bi·​en·​ni·​al | \ (ˌ)bī-ˈe-nē-əl How to pronounce biennial (audio) \

Definition of biennial

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.

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Other Words from biennial

biennial noun
biennially \ (ˌ)bī-​ˈe-​nē-​ə-​lē How to pronounce biennially (audio) \ 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

With the biennial budget that just passed, that support has been extended. Julie Heath,, "Region's Economy: A smart investment for the state of Ohio," 5 Aug. 2019 The assessor, under the FTC’s new order, will be charged with a biennial review of Facebook’s privacy practices. Colin Lecher, The Verge, "Facebook will have to monitor its own privacy rules — and that’s likely not enough," 24 July 2019 Seven artists have asked the museum to remove their work from its biennial showcase of American art over a museum board member’s ties to the sale of law-enforcement supplies including tear gas. Washington Post, "Artists withdraw from NYC museum show over tear gas link," 20 July 2019 The biennial Tex-Mex Fiesta will be held Sept. 6 at the Wallis Annenberg Center of Performing Arts in Beverly Hills. Alexandra Del Rosario, The Hollywood Reporter, "Farrah Fawcett Foundation to Honor Marcia Cross at Tex-Mex Benefit Dinner," 16 July 2019 The number of people in the county living without permanent shelter jumped to about 7,000 in the most recent biennial census, taken over two days in January. Hillary Davis,, "Homeless population grows at Newport Beach bus station," 11 July 2019 More broadly, jetliner sales are traditionally light ahead of the biennial air shows in Paris and Farnborough, England, held during the summer. Sarah Chaney, WSJ, "Boeing Just One Factor Behind Drop in Durable-Goods Orders in May," 26 June 2019 Those on the tour are participating in a biennial conference called Erensya, which brings together Sephardic Jews, descended from people expelled from Spain and Portugal during the Inquisition and settling largely in the Ottoman empire. Nina Shapiro, The Seattle Times, "Jews from around the world come to Seattle to see the U.S.’ 3rd largest Sephardic community," 29 May 2019 Analysts had been voicing concern about the poor early showing for Boeing at the biennial show, the most prestigious in the industry, chalking up the slow deal flow to the woes of its workhorse model, the 737 MAX. Bernhard Warner, Fortune, "Why This Airline CEO Just Bought 200 Boeing 737 MAX Planes—Despite Recent Issues," 19 June 2019

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'biennial.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of biennial

1562, in the meaning defined at sense 1

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Statistics for biennial

Last Updated

11 Aug 2019

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The first known use of biennial was in 1562

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English Language Learners Definition of biennial

: happening every two years
of a plant : living for only two years or seasons : having a life cycle that is two years or seasons long


bi·​en·​ni·​al | \ bī-ˈe-nē-əl How to pronounce biennial (audio) \

Kids Definition of biennial

 (Entry 1 of 2)

1 : occurring every two years a biennial celebration
2 : growing stalks and leaves one year and flowers and fruit the next before dying

Other Words from biennial

biennially \ -​ē-​ə-​lē \ adverb



Kids Definition of biennial (Entry 2 of 2)

: a biennial plant

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More from Merriam-Webster on biennial

Rhyming Dictionary: Words that rhyme with biennial

Spanish Central: Translation of biennial

Nglish: Translation of biennial for Spanish Speakers Encyclopedia article about biennial

Comments on biennial

What made you want to look up biennial? Please tell us where you read or heard it (including the quote, if possible).


not constant or steady

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