biennial

1 biennial /baɪˈɛnijəl/ adjective
1 biennial
/baɪˈɛnijəl/
adjective
Britannica Dictionary definition of BIENNIAL
always used before a noun
1 
: happening every two years
2 
of a plant : living for only two years or seasons : having a life cycle that is two years or seasons long — compare 1annual, 1perennial

— biennially

adverb
2 biennial /baɪˈɛnijəl/ noun
plural biennials
2 biennial
/baɪˈɛnijəl/
noun
plural biennials
Britannica Dictionary definition of BIENNIAL
[count]
: a plant that lives for only two years or seasons : a biennial plant — compare 2annual, 2perennial