bi·en·ni·al | \ (ˌ)bī-ˈe-nē-əl \

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 \ 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 Global Teen Medical Summit is a biennial event started in 2012 by the Health Museum’s Education Team. Alex Park, Houston Chronicle, "Youths explore medicine at Global Teen Medical Summit," 13 July 2018 In 1998 at Royal Melbourne, Mr. Thomson captained the International team to its only victory against the United States in the Presidents Cup, the biennial competition first held in 1994. Dennis Passa, Washington Post, "Peter Thomson, Australian golfer who won the British Open five times, dies at 88," 21 June 2018 The draw for the UEFA Nations League has been made, pitting countries against each other in an exciting new four-tier relegation/promotion biennial competition that promises to breathe fresh life into international football across Europe., "Germany, France, Netherlands Drawn Together in UEFA Nations League," 24 Jan. 2018 The 56-year-old gospel legend was inducted alongside diplomat Teta V. Banks, astronaut Jeanette J. Epps, activist Chantél Harris, and author Margot Lee Shetterly at the sorority’s biennial conference in Houston. Niki Mcgloster,, "The Quick Read: Beyonce, Oprah To Headline Global Citizen in South Africa," 9 July 2018 The biennial Carlisle Journeys conference, run by the Cumberland County Historical Society, is set for the same month. Jeff Gammage,, "The last trip home for boy torn from his family in another century," 20 June 2018 Scotch thistle is a biennial, rising from its first year rosette to bloom and set seed its second year. Margaret Lauterbach, idahostatesman, "Know the proper ways to attack all of our plentiful weeds," 1 June 2018 The University Interscholastic League released its latest biennial district realignment back in Feb. 1 for football and basketball programs that will be in effect for the next two school years. Alvaro Montaño, Houston Chronicle, "Baseball, spring sports learn UIL alignments," 11 Apr. 2018 Big-name Democrats will join thousands of educators in Pittsburgh this weekend when the American Federation of Teachers (AFT) holds its biennial convention. Bradford Betz, Fox News, "Clinton, Sanders, Warren to headline American Federation of Teachers convention in Pittsburgh," 11 July 2018

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

8 Sep 2018

Look-up Popularity

Time Traveler for biennial

The first known use of biennial was in 1562

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More Definitions for biennial



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 \

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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Comments on biennial

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