Read the dictionary definition of biennial. All definitions for this word.
1. (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
2. having a life cycle lasting two seasons
1. a biennial life cycle
2. parsnips and carrots are biennial plants often grown as annuals
3. occurring every second year
1. they met at biennial conventions