biennial (Adjective) — (botany) having a life cycle lasting two seasons. ex. "parsnips and carrots are biennial plants often grown as annuals" ex. "a biennial life cycle"
biennial (Adjective) — Occurring every second year. ex. "they met at biennial conventions"
biennial (Noun) — (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.