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.

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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 Erie Hack, the biannual competition to inspire technological solutions to Lake Erie’s biggest challenges, is back. — Cliff Pinckard, cleveland, 16 Sep. 2021 In 2018, the last year the biannual event was held, the competition welcomed 74 teams from 20 different countries. — NBC News, 11 Sep. 2021 The company also hosts a biannual food festival, Eeeeeatscon, where restaurants serve food in a stadium while musicians and speakers entertain attendees. — Benjamin Mullin, WSJ, 9 Sep. 2021 Following that logic, their biannual magazine, Mother Tongue, is less about mothers than about women who have children. — New York Times, 26 Aug. 2021 What the Bulls do have at their disposal to offer Millsap is their biannual exception, worth about $3.7 million. — Jamal Collier, chicagotribune.com, 1 Sep. 2021 Students have the opportunity to submit a script to the biannual Summer Film Production, which Hodge decided to do for Smile. — Lisa Salinas, Dallas News, 24 Aug. 2021 In addition to paying the employees, B&B, Batali and Bastianich must revise training materials in B&B restaurants and submit biannual reports, providing proof of training and records of harassment and discrimination. — NBC News, 23 July 2021 In Powell’s biannual testimony to Congress this week, these tensions were on full display. — NBC News, 15 July 2021

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.