One (relatively) common usage of biennial (or its Italian spelling biennale) is in the art and cinema community as competitions tend to happen every other year

One (relatively) common usage of biennial (or its Italian spelling biennale) is in the art and cinema community as competitions tend to happen every other year and are called a biennale even in English https://en.wikipedia.org/wiki/Biennale https://en.wikipedia.org/wiki/Biennale