biennal

Biennal is an adjective and sometimes a noun used to describe events or cycles that occur every two years. In English, the standard form is biennial, while biennale (and the less common biennal) are variants often found in the titles of art exhibitions and festivals borrowed from French or Italian. The term is also used in botany to describe plants that complete their life cycle over two growing seasons.

English usage tends to reserve biennial for two-year cycles and biennale for the event itself or to indicate a cultural festival name (as in Venice Biennale). In botanical contexts, a biennial plant typically grows vegetatively in the first year, then flowers and sets seed in the second, before dying.

Biennials are widely associated with contemporary art. They often feature national pavilions, thematic curations, and a rotating roster of international artists, scholars, and visitors. Notable examples include the Venice Biennale (founded 1895), the São Paulo Art Biennial (1951), the Whitney Biennial in New York, and the Istanbul Bienial (since 1992).

Because of spelling variations across languages, the exact usage of biennial, biennale, or biennal varies by region. They are distinct from biannual, which means twice a year in English.