·noun A plant which exists or lasts for two years.
II. Biennial ·adj Happening, or taking place, once in two years; as, a biennial election.
III. Biennial ·noun Something which takes place or appears once in two years; ·esp. a biennial examination.
IV. Biennial ·adj Continuing for two years, and then perishing, as plants which form roots and leaves the first year, and produce fruit the second.