any of a class of solid or semisolid viscous substances obtained either as exudations from certain plants or prepared by polymerization of simple molecules
an abundant nonmetallic tetravalent element occurring in three allotropic forms: amorphous carbon and graphite and diamond; occurs in all organic compounds
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
having a life cycle lasting two seasons; "a biennial life cycle"; "parsnips and carrots are biennial plants often grown as annuals"
occurring every second year; "they met at biennial conventions"