(n) (botany) a plant having a life cycle that normally takes two seasons from germination to death to complete; flowering biennials usually bloom and fruit in the second season
(adj) having a life cycle lasting two seasons, Syn. two-year, Ant. perennial, annual, Example:a biennial life cycle; parsnips and carrots are biennial plants often grown as annuals
a. [ L. biennalis and biennis, fr. biennium a space of two years; bis twice + annus year. Cf. Annual. ] 1. Happening, or taking place, once in two years; as, a biennial election. [ 1913 Webster ]
2. (Bot.) Continuing for two years, and then perishing, as plants which form roots and leaves the first year, and produce fruit the second. [ 1913 Webster ]