MILLENNIUM

noun (plural millennia or -niums) Etymology: New Latin, from Latin mille thousand + New Latin -ennium (as in biennium) Date: circa 1638 1. the thousand years mentioned in Revelation 20 during which holiness is to prevail and Christ is to reign on earth, a period of great happiness or human perfection, 2. a period of 1000 years, a 1000th anniversary or its celebration