Pronunciation: (bī"sen-ten'ē-ul),[key] —adj. 1. pertaining to or in honor of a 200th anniversary: bicentennial celebration; a bicentennial exposition. 2. consisting of or lasting 200 years: a bicentennial period. 3. occurring every 200 years: the bicentennial return of a comet.
—n. 1. a 200th anniversary: The United States had its bicentennial in 1976. 2. a celebration of such an anniversary. Also,esp. Brit.,bicentenary.