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

El Tri remains unbeaten in Gold Cup tests at Mile High, and just got one step closer to claiming its first title in CONCACAF’s biannual summer showcase since 2015. — Sean Keeler, The Denver Post, "Mexico clinches Gold Cup quarterfinals slot with 3-1 win over Canada at Broncos Stadium," 19 June 2019 The Pistons only have the $9.2 million mid-level exception and the $3.6 million biannual exception in free agency to address roster holes. — Vince Ellis, Detroit Free Press, "Detroit Pistons have obvious roster holes entering 2019 NBA draft," 17 June 2019 Southwest Airlines' biannual nationwide sale is currently underway, with plenty of cheap flights out of Louisville Muhammad Ali International Airport. — Lucas Aulbach, The Courier-Journal, "Southwest has 44 cheap flights out of Louisville right now. Here's where you can go," 5 June 2019 While the foundation is perhaps best known for its biannual grants awarded to district teachers for a variety of uses including materials, field trips and guest instructors, the past few months have marked a year of bold changes. — Andrew J. Campa, latimes.com, "Burbank Arts for All Foundation honored at California Capitol," 6 June 2019 This shift was evident at Charles Koch’s biannual private retreat in January, when Stand Together was spotlighted in front of hundreds of donors who each contribute at least $100,000 annually to the network’s wide-ranging agenda. — Washington Post, "Koch network touts latest charity work, downplays politics," 6 June 2019 The past five years have seen the South Korean capital rise to become a real arbiter of style and a biannual destination for editors, buyers, and influencers from around the world. — Monica Kim, Vogue, "The 5 Designers to Know From Seoul Fashion Week Fall 2019," 29 Mar. 2019 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

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.