A millennium is a time period that spans one thousand years or the one-thousand-year anniversary of something. The plural of millennium may be rendered as millennia or as millenniums. Millennium is a Modern Latin word, derived from the Latin word mille which means thousand and the Latin word annus, which means year. As a Latin word, the plural of millennium is rendered as millennia. However, since millennium is now an appropriated English word, it is also correct to render the … Continue reading Millennia vs millenniums