mil·len·ni·um | \mə-ˈle-nē-əm \
plural millennia\-nē-ə \ or millenniums

Definition of millennium 

1a : the thousand years mentioned in Revelation (see revelation sense 3) 20 during which holiness is to prevail and Christ is to reign on earth

b : a period of great happiness or human perfection

2a : a period of 1000 years especially : one reckoned from the beginning of the Christian era at the start of the third millennium

b : a 1000th anniversary or its celebration In 2015 the city of Leipzig, Germany, celebrated its millennium.

Keep scrolling for more

Did You Know?

Since in Latin mille means "thousand", a millennium lasts 1,000 years. Thus, we're living today at the beginning of the third millennium since the birth of Christ. But some religious sects, relying on a prophecy in the biblical Book of Revelation, speak of a coming millennium when Jesus will return to reign on earth for 1,000 years, evil will be banished, and all will live in peace and happiness. Members of these sects who keep themselves in a constant state of preparedness are called millenarians or millennialists.

Examples of millennium in a Sentence

The book describes the changes that have occurred in the landscape over many millennia. The year 2000 was celebrated as the beginning of the third millennium.

Recent Examples on the Web

Francis has continued his predecessors’ efforts at reconciling with the Orthodox church, and held a historic meeting with Kirill in 2016 in Cuba, the first between a pope and Russian patriarch in over a millennium. Washington Post, "Pope denounces ‘murderous indifference’ by powers in Mideast," 7 July 2018 Scientists have discovered evidence that the American swamp sparrow, Melospiza georgiana, has likely been singing the same songs for a millennium. Robert Lachlan, National Geographic, "This Bird Has Been Singing the Same Song for 1,000 Years," 20 June 2018 Women have been objectified for millennia and this city has played its part. Rick Kogan,, "Stormy Daniels is coming to the Admiral Theatre — a moment to talk about sex and this city," 31 May 2018 My neighbors’ houses burned amid the worst drought California had seen in a millennium. Kendra Atleework, The Atlantic, "Power Lines Are Burning the West," 25 May 2018 Authentic helmets – of tooled leather and carved metal, corroded after a millennium underground, often with chain mail hanging – are on show next to metal swords decorated with Indian garnets. Susan Dunne,, "Viking Artifacts, Vinland Map On Display At Mystic Seaport," 22 May 2018 No one questions the location of Israel’s historic capital in Jerusalem, which has been holy to Jews for millennia. Trudy Rubin,, "U.S. Embassy moved to Jerusalem, Gaza exploded. Does Trump or Bibi have a Plan B? | Trudy Rubin," 15 May 2018 Human sacrifice was popular in many religions a millennium ago; the horse went from being essentially the only mode of power transportation 200 years ago to being basically a pet now. Time, "Meet the Founder of Impossible Foods, Whose Meat-Free Burgers Could Transform the Way We Eat," 23 Apr. 2018 Downtown genuinely struggled in the late 20th century and into the new millennium, but it's seen a dynamic resurgence in both business and resident interest in recent years. Maggie Menderski, The Courier-Journal, "Where you can live on a typical income around downtown Louisville," 9 July 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'millennium.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

See More

First Known Use of millennium

circa 1638, in the meaning defined at sense 1a

History and Etymology for millennium

New Latin, from Latin mille thousand + New Latin -ennium (as in biennium)

Keep scrolling for more

Learn More about millennium

Share millennium

Phrases Related to millennium

the millennium

Statistics for millennium

Last Updated

16 Oct 2018

Look-up Popularity

Time Traveler for millennium

The first known use of millennium was circa 1638

See more words from the same year

Keep scrolling for more

More Definitions for millennium



English Language Learners Definition of millennium

: a period of 1,000 years

: a period of a thousand years counted from the beginning of the Christian era


mil·len·ni·um | \mə-ˈle-nē-əm \
plural millennia\-nē-ə \ or millenniums

Kids Definition of millennium

1 : a period of 1000 years

2 : a 1000th anniversary or its celebration

Other Words from millennium

millennial \-nē-əl \ adjective

Keep scrolling for more

Comments on millennium

What made you want to look up millennium? Please tell us where you read or heard it (including the quote, if possible).


lying above or upon

Get Word of the Day daily email!

Test Your Vocabulary

Words from Greek and Roman Mythology Quiz

  • the-triumph-of-venus-by-alessandro-magnasco
  • Boreal comes from the name of the ancient Greek god of which wind?
Name That Thing

Test your visual vocabulary with our 10-question challenge!


Test Your Knowledge - and learn some interesting things along the way.


Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!