multi-millennial

adjective

mul·​ti-mil·​len·​ni·​al ˌməl-tē-mə-ˈle-nē-əl 

-ˌtī-

: involving or occurring over more than two thousand years

We are on the cusp of the next phase of a multimillennial trend (begun when the first maps of the land beyond the horizon were made) that involves more and more of the world being seen at once.

—Daniel Nadler

Word History

First Known Use

1899, in the meaning defined above