quatercentennial,a.|ˌkwætəsɛnˈtɛnɪəl, ˌkweɪtə-| [f. L. quater four times + centennial a. (n.).] Pertaining to a four-hundredth anniversary or celebration. 1964Listener 30 Apr. 730/3 Scholars don't regard their function this quater-centennial year as involving..scratching pocky boils.