Antonym of biennial

Antonyms of noun biennial

Antonyms of adj biennial

2 senses of biennial

Sense 1:

biennial (vs. perennial) (vs. annual), two-year

perennial (vs. annual) (vs. biennial)
annual (vs. biennial) (vs. perennial), one-year

Sense 2:

biennial, biyearly

INDIRECT (VIA periodic) -> aperiodic, nonperiodic