bicentennialnoun [ C ]
us/ˌbɑɪˌsenˈten·i·əl, -sən-/also bicentenary, /ˌbɑɪˌsenˈten·ə·ri, -sən-/the day or year that is 200 years after a particular event, esp. an important one; a 200th anniversary:
The university marked its bicentennial with a weeklong celebration.