The wordbiennialmeans “occurring every two years” and the wordbiannualhas just one meaning: “occurring twice a year.” Therefore, the word biannual is interchangeable with semiannual, although biannual is less preferable if we’d like to avoid any confusion or misunderstanding by anyone who i...
* triennial (every three years) which is sometimes confused with triannual (usually every four months). * biennial (every two years). * biannual (twice a year). ** semiannual (also twice a year). triennial English Adjective (-)