biannual

IPA/baɪˈænjuəl/
KK[baɪˈænuəl]IPA/baɪˈænjuəl/

biannual — adjective

  • biannualpositive
  • more biannualcomparative
  • most biannualsuperlative

1. Taking place, appearing, or being paid two times within a single year.

1.adjectiveC1
Definition

Taking place, appearing, or being paid two times within a single year.

Example

The school sends biannual progress reports to parents in January and June.

collocation: biannual progress reports

Our club holds a biannual book sale each spring and again in autumn.

timing: twice in the same year

Common collocations
  • biannual report
  • biannual sale
  • biannual bonus
  • biannual newsletter
  • biannual meeting
  • biannual review
Synonyms
  • semiannual

    more precise when you want to make the twice-a-year meaning completely clear

  • half-yearly

    same timing, but less common and slightly more British in tone

Antonyms
  • annual

    happening once a year rather than twice within the year

  • monthly

    happening every month rather than only two times a year

Usage Note

Most often used before nouns such as report, sale, bonus, and meeting. In careful modern usage, this sense usually means 'twice a year'; writers who want to avoid ambiguity sometimes choose semiannual instead.

Common Mistakes

The exam is biannual, so it happens every two years.
The exam is biannual, so it happens twice a year.
In its main modern use, biannual means two times within one year, not once every two years.

2. Taking place once in every two-year period rather than every year.

2.adjectiveC1
Definition

Taking place once in every two-year period rather than every year.

Example

Because the science fair is biannual, ninth-grade students can enter only once before graduation.

meaning: once every two years

The town's biannual art show returns in 2028, two years after the last one.

Common collocations
  • biannual art show
  • biannual prize
  • biannual reunion
  • biannual tour
Synonyms
  • biennial

    the clearer and more widely recommended word for this once-every-two-years meaning

Antonyms
  • annual

    happening every year instead of after a two-year gap

  • semiannual

    happening twice in one year rather than once in two years

Usage Note

This older or disputed use means 'once every two years'. Many style guides recommend biennial instead, because readers often understand biannual as 'twice a year'.

Common Mistakes

The festival is biannual, so we see it two times every year.
The festival is biannual, so we see it once every two years.
In this disputed sense, biannual refers to an event that returns after a two-year gap.

Word family

Synonym discussion

Sense: adjective/1

Biannual is useful but tricky because readers do not always agree on what it means. In careful modern use, biannual usually means something happens twice in one year, and in that sense it is close to semiannual. Semiannual is often safer in business or school writing because it removes the ambiguity. Biennial is different: it means once every two years, so it matches only the disputed second sense of biannual. Annual means once each year, while monthly means twelve times a year. For example, a biannual report may come out in June and December, a biennial art show returns after a two-year gap, and an annual festival happens once every year.

biannual ↗semiannualbiennial ↗annual ↗monthly ↗

Common collocations

Nouns

Phrases

  • biannual event
  • biannual meeting
  • biannual report
  • biannual art show

Etymology

LatinEnglish

Biannual combines the prefix bi-, from Latin bis meaning 'twice', with annual, a word built from Latin annus meaning 'year'. In English it first developed the straightforward idea of something happening two times within one year. Because bi- can also be understood as 'every two', the word later gained a second, disputed use for events that return after a two-year gap. That double reading is why many style guides advise writers to choose semiannual for the first meaning and biennial for the second when clarity matters.