millennium

American  

[mi-len-ee-uhm] / mɪˈlɛn i əm /

noun

millenniums, plural millennia plural

1. a period of 1,000 years.

   This great stone monument has seen it all—hardship, plenty, and everything in between—over a millennium and a half.

2. the year 2000, or the turn of the 21st century.

   In 1995, approaching the millennium, the city covered nearly 67,000 acres and had a population of over 1 million.

3. Christianity. the millennium, the period of 1,000 years during which Christ will reign on earth, as an interpretation of a vision set forth by the apostle John in the book of Revelation. Also the Millennium

4. a period of general righteousness and happiness, especially in the indefinite future.

5. a thousandth anniversary.

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millennium British  

/ mɪˈlɛnɪəm /

noun

1. Christianity the period of a thousand years of Christ's awaited reign upon earth

2. a period or cycle of one thousand years

3. a time of peace and happiness, esp in the distant future

4. a thousandth anniversary

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millennium Cultural  

1. A period of a thousand years foretold in the Book of Revelation. During the millennium, those who have been faithful to Jesus and who have not worshiped the Antichrist will reign with Jesus over the Earth. According to the Book of Revelation, the millennium will precede the final battle for control of the universe; Judgment Day will come afterward.

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Discover More

Figuratively, a “millennium” is a period of great justice and happiness on Earth.

The meaning of the Bible's (see also Bible) words about the millennium has been much debated by Christians (see also Christian). Prophecies about the millennium are part of the basic doctrine of several denominations, including Jehovah's Witnesses.

Other Word Forms

Derived Forms

• millennial
  adjective
• millennially
  adverb
• millennialist
  noun

Inflected Forms

noun

• millenniums
  plural
• millennia
  plural

Etymology

Origin of millennium

First recorded in 1630–40; from New Latin, equivalent to Latin mill(e) “a thousand” + -ennium, extracted from biennium, triennium, etc.

Explanation

A decade means ten years, a century means a hundred, and millennium means a thousand. Think: a decade of marriage, the new millennium. In Latin, in the Romance languages, and in the metric system, mille refers to a thousand. A millimeter is a thousandth of a meter, a milliliter a thousandth of a liter, a millennium is a thousand years. Think of the number "one million" as a thousand thousands, and you'll get the idea.

Example Sentences

"Around the millennium, everyone was just told no – you don't take part in any sport, not even recreational," says Dr. Lahti.

From BBC • Jun. 8, 2026

A root used for more than a millennium may not replace today's treatments yet, but it could help guide the next generation of hair regrowth therapies.

From Science Daily • Jun. 7, 2026

Consumer prices have almost exactly doubled in the U.S. since the start of the millennium, so today’s $1 trillion would “only” be worth about $500 billion in 1999 dollars.

From MarketWatch • Jun. 5, 2026

And again, that hope that they were this modern couple, one that we’ve never seen before, and what will they become in this new millennium?

From Los Angeles Times • Jun. 4, 2026

It was the end of an imperial tradition that dated back to Teotihuacan a millennium before.

From "1491" by Charles C. Mann