adjective Also biyearly (for defs 1, 2).
Related formsbi·en·ni·al·ly, adverb
Examples from the Web for biennially
Legislature and State officers elected quadrennially; members Congress, biennially.Alden's Handy Atlas of the World|John B. Alden
This can be done annually or biennially according to whether the plants are growing strongly or not.Trees and Shrubs for English Gardens|Ernest Thomas Cook
The congress was to meet annually in time of common war, and biennially in times of peace.Martin Van Buren|Edward M. Shepard
In some states the legislatures meet annually; in others, biennially.Why We Punctuate|William Livingston Klein
Both were biennially elected, and the compensation of each was fixed at 5% on the amount of the state tax assessed and collected.