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 Two days after Utahns set their clocks forward in time for the biannual time change, the U.S. Senate on Tuesday unanimously passed a bill that would make daylight saving time permanent throughout the country by the end of 2023. — Kim Bojórquez, The Salt Lake Tribune, 17 Mar. 2022 On April 30, the coalition will be holding a biannual Drug Take-back Day, encouraging people to drop off unused prescription medication. — Steve Smith, Hartford Courant, 14 Apr. 2022 The company began publishing biannual transparency reports in 2019 and bars those under 13 from Discord. — New York Times, 29 Dec. 2021 Even runway fashion, which is supposed to move at a slower, biannual speed, has joined this rat race, as designers pack their shows with potential viral moments and styles that are replicable by anyone with a little ingenuity and a pair of scissors. — Rachel Tashjian, Harper's BAZAAR, 5 Apr. 2022 And for more than a decade, Pace, who earlier in his career worked for both the Metropolitan Museum of Art and the Guggenheim in New York, has also run Nomad, an itinerant biannual design fair. — New York Times, 22 Mar. 2022 But the confusing and often disruptive biannual practice, which has been associated with adverse effects on health and public safety, may become a relic of the past. — Washington Post, 18 Mar. 2022 Ending the biannual clock-changing is fairly popular among voters. — Matt Ford, The New Republic, 18 Mar. 2022 Since the bill's introduction in March 2021 by Rubio, its co-sponsors have argued the biannual time switch negatively impacts Americans' lives. — Rick Klein, ABC News, 16 Mar. 2022 See More

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.