bi·​an·​nu·​al | \ (ˌ)bī-ˈan-yə(-wə)l How to pronounce biannual (audio) \

Definition of biannual

1 : occurring twice a year

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Other Words from biannual

biannually 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?

When we describe something as biannual, we can mean either that it occurs twice a year or that it occurs once every two years. So how does someone know which particular meaning we have in mind? Well, unless we provide them with a contextual clue, they don't. Some people prefer to use semiannual to refer to something that occurs twice a year, reserving biannual for things that occur once every two years. This practice is hardly universal among English speakers, however, and biannual remains a potentially ambiguous word. Fortunately, English also provides us with biennial, a word that specifically refers to something that occurs every two years or that lasts or continues for two years.

Examples of biannual in a Sentence

Politicians still tremble when Barry begins his biannual comeback flirtations.  … But if they'd spent less time looking over their shoulders and more time looking over election returns, they'd have seen that Barry was likely heading for a poleaxing when he called it quits. — Michael Schaffer, New Republic, 22 Apr. 2002 … have recommended routine annual or biannual mammographic screening for asymptomatic women without a personal or family history of breast cancer, starting at the age of 40. — Nels Marcus Thygeson, Journal of the American Medical Association, 8 July 1986 One of the more fascinating commonplace facts about the whitetail is its biannual change of color. Summer, when deer come "into the red," as the saying goes, scant reddish-brown hairs replace the winter coat. Fall, deer come back "into the blue," though less than blue, with a thick pelage of hollow, grayish-tan hairs … — John G. Mitchell, Smithsonian, November 1982 The group holds biannual meetings in December and July. The art show is a biannual event that won't happen again for two more years.
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Recent Examples on the Web Tahura Holly planned to travel from India to Michigan in May to host her biannual jewelry pop-up shop. Nargis Rahman, Detroit Free Press, "They do weddings for multicultural brides. COVID-19 is disrupting their plans.," 15 Aug. 2020 Take Shelma Jun, for example, whose community Flash Foxy not only encourages women to spend time in local climbing gyms, but also hosts biannual festivals for female climbers to connect and learn from each other. Cnt Editors, Condé Nast Traveler, "A Guide to the Outdoors, For Women and By Women," 11 Aug. 2020 The 2021 edition will combine Salone’s biannual exhibitions, including the Euroluce lighting show and EuroCucina, focused on kitchens. Ingrid Abramovitch, ELLE Decor, "Milan's Famous Furniture Fair Has Been Postponed Until 2021," 27 Mar. 2020 Lawmakers believed, once upon a time, that a biannual time change would save energy during wartime. Krista Kafer, The Denver Post, "Kafer: Time for no change when it comes to Colorado’s daylight saving time change," 14 Feb. 2020 Frustration with the narrow vision of mainstream publications is part of what inspired the chef and author Klancy Miller, who is black, to conceive of For the Culture, a biannual print magazine dedicated to celebrating black women in food and wine. Hannah Giorgis, The Atlantic, "The Table Stays White," 16 June 2020 In biannual tax expenditure reports that begin in 1997, the Oregon Department of Revenue estimates the total amount of money lost to the special assessments. Lylla Younes, ProPublica, "How We Analyzed Data From Oregon’s Timber Industry," 11 June 2020 In biannual tax expenditure reports that begin in 1997, the Oregon Department of Revenue estimates the total amount of money lost to the special assessments. oregonlive, "How we analyzed data from Oregon’s timber industry," 11 June 2020 Coercive behavior is punishable with five years in prison, and in 2018 and 2019, nearly 1,200 people were charged with the offense, according to a biannual report by the Crown Prosecution Service. Elian Peltier,, "Abused woman who killed husband is granted the family’s UK estate," 1 June 2020

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'biannual.' 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 biannual

1877, in the meaning defined at sense 1

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The first known use of biannual was in 1877

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Last Updated

18 Aug 2020

Cite this Entry

“Biannual.” Dictionary, Merriam-Webster, Accessed 18 Sep. 2020.

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More Definitions for biannual


How to pronounce biannual (audio)

English Language Learners Definition of biannual

: happening twice a year
: happening every two years

More from Merriam-Webster on biannual

Nglish: Translation of biannual for Spanish Speakers

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