biannual

/baɪˈænjuəl/ (bre, ipa) · /baɪˈænjuəl/ (ame, ipa) · /(ˌ)bī-ˈan-yə(-wə)l/ (ame, mw)

biannual — 形容詞

  • biannualpositive
  • more biannualcomparative
  • most biannualsuperlative

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

1.形容詞C1
釋義

一年兩次的

一年內發生、出版或支付兩次的

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

例句

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

學校在一月和六月各寄一次成績報告給家長。

collocation: biannual progress reports

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

我們的社團每年春天和秋天各辦一次書籍義賣。

timing: twice in the same year

同義詞
  • 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

反義詞
  • annual

    happening once a year rather than twice within the year

  • monthly

    happening every month rather than only two times a year

用法筆記

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.

常見錯誤

❌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.形容詞C1
釋義

兩年一次的

每隔兩年才發生一次的

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

例句

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

因為科展每隔兩年才舉辦一次，九年級學生畢業前只能參加一次。

meaning: once every two years

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

鎮上的藝術展是兩年一次，所以下一屆要到 2028 年才回來。

同義詞
  • biennial

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

反義詞
  • annual

    happening every year instead of after a two-year gap

  • semiannual

    happening twice in one year rather than once in two years

用法筆記

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'.

常見錯誤

❌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.