biannual

American  

[bahy-an-yoo-uhl] / baɪˈæn yu əl /

adjective

1. occurring twice a year; semiannual.

2. occurring every two years; biennial.

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biannual British  

/ baɪˈænjʊəl /

adjective

1. occurring twice a year Compare biennial

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Usage

What does biannual mean? Biannual can mean two things: occurring once every two years or occurring twice per year. Biannual is a synonym of biyearly, which can also be used to mean every two years or twice per year. (Biyearly can also mean “lasting for two years,” but this meaning is rarely used.)The adverb form of biannual is biannually. Examples:

• The Olympic Games are biannual, meaning they happen every two years.
• This is a biannual meeting—we have it in April and October.

Commonly Confused

See bi- ¹.

Other Word Forms

• biannually adverb

Etymology

Origin of biannual

First recorded in 1875–80; bi- ¹ + annual

Compare meaning

How does biannual compare to similar and commonly confused words? Explore the most common comparisons:

• biannual vs. semiannual

Explanation

Use biannual to describe something that happens two times a year. Cleaning out the garage may be a biannual project in your household, or your dentist might insist on biannual check-ups. When you break apart the word biannual, it’s easy to remember what it means. The prefix bi-, meaning “two,” tips you off that this is something that happens twice. And you’re probably already familiar with annual, which describes something that happens once a year. Put it together and you have biannual: twice a year. Whether you’re describing formal events or the frequency of your haircuts, you can use biannual anytime you need to say that something happens twice a year.

Example Sentences

Other initiatives by ExpressVPN are too numerous to list here, but you can read its biannual transparency report for more information.

From Salon • Apr. 1, 2026

Researchers compared consumers’ year-ahead inflation expectations with those of professional forecasters tracked by the biannual Livingston Survey of economists and the quarterly Survey of Professional Forecasters, both conducted by the Philadelphia Fed.

From Barron's • Feb. 6, 2026

It was initially a counterpoint to the Pusser museum’s biannual official bus tour, though this year’s was postponed amid the fallout from the TBI investigation.

From Slate • Nov. 6, 2025

“I haven’t seen a game for the last 46 years,” the lexicographer said, though he makes a biannual exception for the second halves of the Super Bowl and college football’s national championship game.

From Los Angeles Times • Oct. 30, 2025

One was a deep brown, with scrapes and scratches visible beneath the glossy veneer she kept up with biannual waxing.

From "Warriors Don't Cry: A Searing Memoir of the Battle to Integrate Little Rock's Central High" by Melba Pattillo Beals

Related Words

• semiannual