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 biennial (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 The state’s new biennial budget, which was released Friday, seeks to strengthen Maine's pandemic response without raising tax rates, WGME reported. Sarah Downey, Washington Examiner, "Pandemic expected to once again dominate Maine lawmakers' priorities," 19 Jan. 2021 That would be one week ahead of the start of the 2021 legislative session when 181 lawmakers and their staffs will report to the building for their biennial session. James Barragán, Dallas News, "Texas Capitol will re-open to the public on Jan. 4," 21 Dec. 2020 Goldberg’s office, which is not legally required to perform the biennial analysis but since 2018 has done so by default, determined that constitutional officers are entitled to a 4.89 percent pay raise, starting Friday. Matt Stout,, "Mass. legislative leaders to get three pay raises starting Friday," 31 Dec. 2020 New and old versions of the site still exist, much of it still coded in Flash — which means that time is running out to see pieces of this biennial cybersquat unless it gets fully upgraded. Los Angeles Times, "Why the end of Flash animation marks the end of an era for creativity on the web," 28 Dec. 2020 ProjectDiane is a biennial demographic study that tracks public funding announcements for Black women and Latina entrepreneurs. Jessica Guynn, USA TODAY, "Racial inequity persists after George Floyd: Black women and Latina entrepreneurs get less than 1% of venture capital," 3 Dec. 2020 The chamber’s biennial study uses 2019 data from the Texas Workforce Commission, UT Health San Antonio, the Baylor College of Medicine and military entities in San Antonio. Laura Garcia,, "Health care, bioscience overtake military as San Antonio area’s top money-generating industry," 18 Nov. 2020 Ninety Latinx women have also raised the same amount, according to ProjectDiane, a biennial report on the subject. David Meyer, Fortune, "Which companies will still be thriving decades from now?," 3 Dec. 2020 In fact, the number of Black women who have raised over $1 million in funding has more than doubled since 2018, according to ProjectDiane, a biennial report released Wednesday. CNN, "Black women don't get much startup funding. These founders are trying to change that," 2 Dec. 2020

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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Time Traveler for biennial

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The first known use of biennial was in 1562

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Last Updated

12 Feb 2021

Cite this Entry

“Biennial.” Dictionary, Merriam-Webster, Accessed 1 Mar. 2021.

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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 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

More from Merriam-Webster on biennial

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

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