Biyearly can mean two things: occurring once every two years or occurring twice per year. Biyearly is a synonym of biannual (and biannually), which can also be used to mean every two years or twice per year.

What does it mean half-yearly?

Definitions of half-yearly. adjective. occurring or payable twice each year. synonyms: biannual, biyearly, semiannual periodic, periodical. happening or recurring at regular intervals.

What is every 2 years called?

1 : occurring every two years a biennial celebration. 2 : continuing or lasting for two years specifically, of a plant : growing vegetatively during the first year and fruiting and dying during the second Biennial herbs flower in their second year.