BIEN'NIAL, adjective [Latin biennis, of bis, twice, and annus, a year.] 1. Continuing for two years and then perishing; as plants, whose root and leaves are formed the first year, and which produce fruit the second. 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.
Source: Webster's 1828 American Dictionary ↗ · public-domain · returned verbatim, no AI