Wiktionary
bimillennial
a. Occurring every two thousand (2,000) years. n. The 2,000th anniversary of an event or happening.
Usage examples of "bimillennial".
The almost universal theme of the writers and orators who have celebrated this bimillennial epoch has been the future rather than the past, not the advance that has been made, but the progress that shall be made, ever onward and upward, till the race shall achieve its ineffable destiny.