Biennial
/baɪˈɛn.i.əl/noun
Occurring every two years, or living for two years.
Did you know?Its core comes from Latin bi- (“two”) + annus (“year”), the same root behind anniversary, annual, and perennial—words all built around the ancient power of marking time.
Etymological Timeline
Proto-Indo-European
PIE
*h₂et-
“year, season”
Latin
Latin
annus
“year”
Latin
Latin
biennium
“a period of two years”
Late Latin
Latin
biennalis
“lasting or occurring for two years”
Middle English
English
biennial
“lasting two years; occurring every two years”
Modern English
English
biennial
“occurring every two years, or living for two years”
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