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  • Word comparison: biannual vs. semiannual

biannual vs. semiannual

biannual vs. semiannual: What's the difference?

Biannual and semiannual can both mean “twice a year.” However, biannual can also mean “every two years,” and semiannual can also mean “lasting for half a year” (though this sense isn’t commonly used). The best way to be clear is to just say “twice a year” or “every two years.”

biannual

adjective

  1. occurring twice a year; semiannual.

  2. occurring every two years; biennial.

semiannual

adjective

  1. Also occurring, done, or published every half year or twice a year; biannual.

  2. lasting for half a year.

    a semiannual plant.