Definition of BIANNUAL

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.

Recent Examples on the Web

The biannual show circuit feels like a circus, to be sure. — Laird Borrelli-persson, Vogue, "Fashion Loves a Clown: Here, 24 Big Top Looks That Prove It From Dior Haute Couture to Alexander McQueen," 21 Jan. 2019 The issue initially gained momentum when 70,000 Finnish citizens signed a petition to end biannual time changes, and Ireland Member of European Parliament (MEP) Sean Kelly has been an outspoken critic of Daylight Saving Time as well. — Megan Geuss, Ars Technica, "EU Commission President supports ending seasonal time changes," 31 Aug. 2018 Now in its 95th edition, Pitti Uomo has long served as a biannual hunting ground for street-style photographers who document the outfits of men’s fashion-industry insiders. — Jacob Gallagher, WSJ, "Inside the Bizarre Life of a Male Street-Style Star," 14 Jan. 2019 On Wednesday, at the company's biannual Hack Day, Netflix unveiled a new feature called EyeNav, which allows users to navigate the iOS version of the app using only eye movements and facial expressions, including sticking out your tongue. — Sam Blum, Popular Mechanics, "Kooky Netflix Hack Lets You Navigate the App Using Only Eye and Facial Movements," 8 Nov. 2018 As part of the spring 2015 One Room Design Challenge—a biannual blogger event organized by the blog Calling it Home—20 bloggers accepted the challenge of completely making over a single space in their homes in under six weeks. — Lauren Matthews, Country Living, "5 Design Takeaways From One of the Most Beautiful DIY Bathroom Renovations Ever," 15 May 2015 The Treasury’s official biannual report that is used to formally designate a country as a currency manipulator is expected in coming days. — Josh Zumbrun, WSJ, "Mnuchin Says a Trump-Xi Trade Summit Is No Done Deal," 13 Oct. 2018 In its biannual forecast released on Thursday, the European Commission raised its projection for Hungaryʼs GDP growth this year to 4.3% (up from 4.0% forecast in the spring), and to 3.4% for 2019 (up from 3.2%), state news agency MTI reported. — James Freeman, WSJ, "One Thing Investors Don’t Need to Worry About," 20 Nov. 2018 Last week, an international crowd arrived in Johannesburg for the city’s biannual South African Fashion Week. — Amira Rasool, Vogue, "Meet the Instagram-Sensation Design Duo Changing the Look of South African Fashion," 16 Apr. 2018

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.