biennial

American  

[bahy-en-ee-uhl] / baɪˈɛn i əl /

adjective

1. happening every two years.

   biennial games.

2. lasting or enduring for two years.

   a biennial life cycle.

3. Botany. completing its normal term of life in two years, flowering and fruiting the second year, as beets or winter wheat.

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noun

1. any event occurring once in two years.

2. Botany. a biennial plant.

biennial British  

/ baɪˈɛnɪəl /

adjective

1. occurring every two years

2. lasting two years Compare biannual

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noun

1. a plant, such as the carrot, that completes its life cycle within two years, developing vegetative storage parts during the first year and flowering and fruiting in its second year Compare annual perennial

2. an event that takes place every two years

biennial Scientific  

/ bī-ĕn′ē-əl /

1. Completing a life cycle normally in two growing seasons.

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1. A biennial plant. In the first year, biennials normally produce a short stem, a rosette of leaves, and a fleshy root that acts as food supply. In the second season, biennials blossom, produce seed, use up their food supply, and die. Carrots, parsnips, and sugar beets are examples of biennials.

2. Compare annual perennial

Commonly Confused

See bi- ¹.

Other Word Forms

• biennially adverb

Etymology

Origin of biennial

First recorded in 1615–25; bienni(um) + -al ¹

Explanation

If you’re just as fanatical about the luge as you are about beach volleyball, you probably know that the Olympic Games are on a biennial schedule. Every two years, either the Summer or the Winter Olympics takes place. Don't mistake biennial for biannual, which means “twice a year.” Annoying? Yes, but other words containing the prefix bi- are even more troublesome. For example, bimonthly can mean either “twice a month” or “every two months.” To avoid confusion, you can use the prefix semi- to mean “twice during a certain time period.” So, it’s correct to say that the Olympics occurs on a biennial schedule, not on a semiannual (or biannual) one.

Example Sentences

However, he has only won the biennial showpiece once in 1999 - at Brookline in Massachusetts.

From BBC • Apr. 1, 2026

Pondering her return to sculpture after several decades as an acclaimed performance and conceptual artist, Fraser notes that the L.A. artists in this year’s biennial are united by the intersection of conceptual art and craft.

From Los Angeles Times • Mar. 10, 2026

The WTO is holding its ministerial conference, its biennial main gathering, in late March in Cameroon.

From Barron's • Feb. 13, 2026

Previously an annual showpiece event, it was cut to biennial from 2011.

From BBC • Jan. 8, 2026

Once the first two crates were completed, I carried them down to the art museum for consideration in their upcoming juried biennial.

From "Me Talk Pretty One Day" by David Sedaris

Related Words

• flower
• grass
• herb
• seedling
• shrub
• tree
• vine
• weed