biennial

/baɪˈeniəl/ (bre, ipa) · /baɪˈeniəl/ (ame, ipa) · /(ˌ)bī-ˈe-nē-əl/ (ame, mw) · /baɪˈen.i.əl/ (bre, ipa) · /baɪˈen.i.əl/ (ame, ipa)

biennial — adjective

  • biennialpositive
  • more biennialcomparative
  • most biennialsuperlative

1. describing an event, activity, or official process that happens once in every tw

1.形容詞B1
釋義

describing an event, activity, or official process that happens once in every two years, so there is a full year with no occurrence in between.

例句

The biennial conference on climate policy brings together scientists from forty nations.

biennial conference

Henry missed the biennial election because he was working overseas that year.

同義詞
  • two-yearly

    less formal synonym, often used in British English

  • once every two years

    a phrase paraphrase used when biennial might cause confusion with biannual

反義詞

文法句型

biennial + noun

be + biennial

用法筆記

Frequently confused with biannual, which means 'twice a year' rather than 'once every two years.' When you need to make the meaning completely clear, consider saying 'once every two years' instead.

常見錯誤

The committee holds a biannial meeting every two years.
The committee holds a biennial meeting every two years.
💡Biannial is not a word; the correct form is biennial for every two years.
We have a biennial check-up twice a year.
We have a semiannual check-up twice a year.
💡Biennial means every two years, not twice a year.

2. lasting or continuing through a period of two years — for example, a plant that

2.形容詞B2
釋義

lasting or continuing through a period of two years — for example, a plant that grows leaves in its first season and flowers in its second, or a course of study that runs across two full academic years.

例句

The farmer explained that onions are biennial crops, though most are harvested yearly.

biennial crops

Deepa learned that foxgloves follow a biennial pattern, blooming only in their second year.

biennial pattern

同義詞
  • two-year

    used informally for plants, programs, or contracts lasting two years

  • two-season

    used in gardening contexts to describe the growth pattern

反義詞
  • annual

    completing a life cycle in one growing season

  • perennial

    living for three or more growing seasons

文法句型

biennial + noun

be + biennial

用法筆記

This sense describes something that lasts or continues for two years, whether a plant's life cycle, a fixed-term program, or another two-year span. In botany, a biennial plant is distinct from an annual (one season) and a perennial (many seasons). Common biennials include carrots, parsley, foxgloves, and onions.

常見錯誤

A biennial plant flowers in its first year.
A biennial plant flowers in its second year.
💡Biennials produce leaves and roots in the first year and only flower in the second year.

biennial — noun