Biannual vs biennial
Biannual means happening twice a year. Biennial means happening once every two years.
A biennial plant lives two years, and a biennial event comes every two years.
biannual adjective
Happening two times every year.
- The two presidents agreed to hold biannual meetings, one in each capital.
- We have a biannual sale, once in spring and once in fall.
biennial adjective
Happening one time every two years.
- The committee publishes a biennial report on the health of the river.
- The art show is biennial, so if you miss this one, you will wait two years for the next.
Watch out
- Some people use biannual to mean once every two years. A few dictionaries record this, but most usage guides call it a mistake. Use biennial for every two years.
- Biennial is also a noun for a plant that takes two years to finish its life, usually flowering in the second year.Parsley is a biennial, though most cooks pull it up after the first season.
Test yourself
The dentist recommends blank checkups, one in January and one in July.
Show answer
biannual. Two checkups each year means biannual.
The festival is blank, held every other summer.
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biennial. Every other summer means once every two years, so biennial.
Our blank newsletter comes out every June and December.
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biannual. It comes out twice each year, so biannual.
The blank conference takes place only in odd-numbered years.
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biennial. Only in odd-numbered years means once every two years, so biennial.
Full entries: biannualbiennial