[ bahy-yeer-lee ]
/ baɪˈyɪər li /
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every two years; biennially; biannually.
twice yearly.
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Origin of biyearly

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

words often confused with biyearly

See bi-1.

Words nearby biyearly

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2022


What does biyearly mean?

Biyearly can mean two things: occurring once every two years or occurring twice per year.

Biyearly is a synonym of biannual (and biannually), 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 Olympic Games occur biyearly, meaning they happen every two years.
  • This is a biyearly meeting—we have it in April and October.

Where does biyearly come from?

The first records of biyearly being used in English come from the 1870s. Bi- is a prefix meaning “twice” or “two,” and yearly means “happening every year” or “once a year.”

People are often confused about whether to use biyearly or biannual and for good reason: both can mean “twice per year” or “every other year.” The thing to remember is that one isn’t more “correct” than the other. However, biyearly appears less commonly than biannual.

There are several other similar time-related terms that can make things even more confusing. Semiannual and semiyearly both mean occurring twice a year or lasting for half a year. Another word, biennial, means happening every two years or lasting for two years, but this is used less commonly than biyearly or biannual.

Yes, you can sometimes figure out what biyearly means through the context of the sentence. But not always. When a coworker tells you a meeting is biyearly, it probably means it happens twice a year, but it could also mean it happens every two years. (Hopefully it doesn’t mean that it lasts for two years.)

Here’s the best (and maybe only) way to be perfectly clear: just say “twice a year” or “once every two years.”

Did you know ... ?

What are some synonyms for biyearly?

What are some words that share a root or word element with biyearly

What are some words that often get used in discussing biyearly?

What are some words biyearly may be commonly confused with?

How is biyearly used in real life?

Biyearly is perhaps most commonly used to describe events that occur every two years, such as the Olympics, but this isn’t always the case, so it’s always best to make sure.



Try using biyearly!

What of the following words can be a synonym for biyearly?

A. biannual
B. biannually
C. biennial
D. all of the above

British Dictionary definitions for biyearly

/ (baɪˈjɪəlɪ) /

adjective, adverb
every two years; biennial or biennially
(often avoided because of confusion with sense 1) twice a year; biannual or biannuallySee bi- 1
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012