The definition of biyearly is something that happens once every two years.
An example of something biyearly is the Olympics.
- once every two years; biennial(ly)
- Now Rare twice a year: in this sense, semiyearly, semiannual(ly), or biannual(ly) is preferred
- Happening every two years. See Usage Note at bi–1.
- Happening twice a year; semiyearly.
- Every two years.
- Twice a year; semiyearly.