biennial
adjective uk/baɪˈen.i.əl/ us/baɪˈen.i.əl/
两年一次的
happening once every two years
Compare: annual adjectivebiannual
biennial
noun [ C ] uk/baɪˈen.i.əl/ us/baɪˈen.i.əl/
（第二年开花的）两年生植物
a plant that lives for two years, producing seeds and flowers in its second year
Compare: annual adjectivebiannualperennial noun