bicentennial

UK: /ˌbaɪsɛnˈtɛnɪəl/ US: /ˌbaɪsɛnˈtɛniəl/ ,(bī′sen ten′ē əl)

WordReference Random House Learner's Dictionary of American English © 2026

bi•cen•ten•ni•al /ˌbaɪsɛnˈtɛniəl/   adj. [before a noun]

1. relating to or in honor of a 200th anniversary.
2. lasting 200 years.
3. occurring every 200 years.

n. [countable]

4. a 200th anniversary.

See -enn-.

WordReference Random House Unabridged Dictionary of American English © 2026

bi•cen•ten•ni•al  (bī′sen ten′ē əl), 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. 

4. a 200th anniversary:
   The United States had its bicentennial in 1976.
5. a celebration of such an anniversary.

Also,[esp. Brit.,] bicentenary. 

• bi-¹ + centennial 1880–85

bi′cen•ten′ni•al•ly, adv. 
Usage

See bi- ¹.