bi·​en·​ni·​al | \ (ˌ)bī-ˈe-nē-əl How to pronounce biennial (audio) \

Definition of biennial

1 : occurring every two years a biennial celebration
2 : continuing or lasting for two years specifically, of a plant : growing vegetatively during the first year and fruiting and dying during the second Biennial herbs flower in their second year.

Keep scrolling for more

Other Words from biennial

biennial noun
biennially \ (ˌ)bī-​ˈe-​nē-​ə-​lē How to pronounce biennially (audio) \ adverb

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?

Biennial conventions, celebrations, competitions, and sports events come every two years. Biennials are plants that live two years, bearing flowers and fruit only in the second year. (Carrots and sugar beets are two examples; since we're only interested in their roots, we don't wait another year to see their flower and fruit.) In contrast, semiannual means "twice a year". But no one can agree whether biweekly means "twice a week" or "every two weeks", and whether bimonthly means "twice a month" or "every two months". Maybe we should stop using both of them until we can decide.

Examples of biennial in a Sentence

The governor explained the biennial budget proposal.
Recent Examples on the Web The 2020 Painting and Drawing Faculty Exhibition is part of a biennial installment., "Community News For The Windham Edition," 4 Sep. 2020 Efforts at state funding last year for beach nourishment and a local match for a study of long-term solutions by the U.S. Army Corps of Engineers failed after it was placed in the state’s biennial budget and then removed at the last minute. Amy Lavalley,, "Lake Michigan beach nourishment program: ‘Will it last 10 years or 10 minutes?’," 2 Sep. 2020 Esper's stop in Hawaii will come as the US wraps up biennial RIMPAC exercises in Hawaii. Brad Lendon, CNN, "China says US U-2 spy plane disrupted its military exercises," 26 Aug. 2020 The 2021 spending plan, released a year ago in more prosperous times as the second year of the county's biennial budget, had called for a 4.5% increase in the levy. Shannon Prather, Star Tribune, "Ramsey County Board drops 2021 tax levy, now proposing zero increase," 25 Aug. 2020 Sugar beets are a biennial vegetable, and a single plant can produce mature roots that weight between two and four pounds. The Editors, Field & Stream, "Three Things to Consider Before Buying Food Plot Seed," 24 Aug. 2020 The budget request, announced by UW System Interim President Tommy Thompson Tuesday, would increase the system's upcoming biennial budget by $95.7 million. Devi Shastri, Milwaukee Journal Sentinel, "Tommy Thompson seeks 3.5% UW System budget increase to expand Bucky's Tuition Promise, fund other initiatives," 18 Aug. 2020 Lamont must propose a plan to legislators in February to balance that biennial cycle, which runs from July 2021 through June 2023., "Post pandemic reality: Gov. Lamont tells state agencies to prepare for deep cutting in next budget," 17 Aug. 2020 Those are among the key takeaways from a biennial survey of Irving residents. Sarah Bahari, Dallas News, "Residents enjoy Irving’s quality of life but wish the city was better looking, survey says," 6 Aug. 2020

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'biennial.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

See More

First Known Use of biennial

1562, in the meaning defined at sense 1

Keep scrolling for more

Learn More about biennial

Time Traveler for biennial

Time Traveler

The first known use of biennial was in 1562

See more words from the same year

Statistics for biennial

Last Updated

15 Sep 2020

Cite this Entry

“Biennial.” Dictionary, Merriam-Webster, Accessed 18 Sep. 2020.

Keep scrolling for more

More Definitions for biennial


How to pronounce biennial (audio)

English Language Learners Definition of biennial

: happening every two years
of a plant : living for only two years or seasons : having a life cycle that is two years or seasons long


bi·​en·​ni·​al | \ bī-ˈe-nē-əl How to pronounce biennial (audio) \

Kids Definition of biennial

 (Entry 1 of 2)

1 : occurring every two years a biennial celebration
2 : growing stalks and leaves one year and flowers and fruit the next before dying

Other Words from biennial

biennially \ -​ē-​ə-​lē \ adverb



Kids Definition of biennial (Entry 2 of 2)

: a biennial plant

More from Merriam-Webster on biennial

Nglish: Translation of biennial for Spanish Speakers Encyclopedia article about biennial

Comments on biennial

What made you want to look up biennial? Please tell us where you read or heard it (including the quote, if possible).


Test Your Vocabulary

Dog Words Quiz

  • shiba puppy more or less demanding cuddles
  • Which of the following animals has a dog in its etymology?
Spell It

Can you spell these 10 commonly misspelled words?

Dictionary Devil

Test Your Knowledge - and learn some interesting things along the way.

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!