what is biennial?
1. 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. Familiarity information: BIENNIAL used as a noun is very rare. â¢ BIENNIAL (adjective). The adjective BIENNIAL has 2 senses: 1. occurring every second year. 2. having a life cycle lasting two seasons. Familiarity information: BIENNIAL used as an adjective is rare.