[bahy-an-yoo-uh l]


occurring twice a year; semiannual.
occurring every two years; biennial.

Origin of biannual

First recorded in 1875–80; bi-1 + annual
Related formsbi·an·nu·al·ly, adverb
Can be confusedbiannual biennial semiannual (see usage note at bi-1)

Usage note

See bi-1. Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for biannually

Historical Examples of biannually

  • The economic assessment of the country is assessed quarterly and biannually.

    After the Rain

    Sam Vaknin

British Dictionary definitions for biannually



occurring twice a yearCompare biennial
Derived Formsbiannually, adverb
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for biannually



also bi-annual; "occurring every six months, twice a year," 1837, from bi- + annual. Related: Biannually; bi-annually.

Online Etymology Dictionary, © 2010 Douglas Harper