biennial

Adjective

• occurring every second year
  • they met at biennial conventions
    

• having a life cycle lasting two seasons
  • a biennial life cycle
    
  • parsnips and carrots are biennial plants often grown as annuals
    

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

Related words

• Synonyms: 
  biyearly , two-year
• Antonyms: 
  perennial , annual , one-year