Emily Dickinson Lexicon

BI-EN'NI-AL, a. [L. biennis, of bis, twice, and annus, a year.]

1. Continuing for two years; or happening, or taking place once in two years; as, a biennial election.
2. In botany, continuing for two years and then perishing; as plants, whose root and leaves are formed the first year, and which produce fruit the second. – Martyn.