millennium
n. countablen. a period of one thousand years. It is often used to talk about a specific date in history or a very long time.
n. a period of one thousand years, especially one calculated from the beginning of the Christian era. Often used to refer to the anniversary of such a period.
The ancient ruins have stood for over a millennium.
The world celebrated the start of a new millennium on January 1, 2000, with massive fireworks displays.
Geologists measure the movement of tectonic plates over many millennia, as the slow shifts that shape our continents are imperceptible within a single human lifetime.
From Late Latin mīllennium, from Latin mīllennis (“1000-year”) + -ium (forming abstract nouns).
The plural form is 'millennia', though 'millenniums' is also accepted in modern usage.
milleniummillenniumLearners often forget the second 'n'; the word is spelled with a double 'l' and a double 'n'.