trillion

American  

[tril-yuhn] / ˈtrɪl jən /

noun

trillions, plural trillion plural

1. a cardinal number represented in the U.S. by 1 followed by 12 zeros, and in Great Britain by 1 followed by 18 zeros.

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adjective

1. amounting to one trillion in number.

trillion British  

/ ˈtrɪljən /

noun

1. the number represented as one followed by twelve zeros (10 ¹² ); a million million

2. (formerly, in Britain) the number represented as one followed by eighteen zeros (10 ¹⁸ ); a million million million

3. (often plural) an exceptionally large but unspecified number

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determiner

1. 1. amounting to a trillion

      a trillion stars

   2. ( as pronoun )

      there are three trillion

Other Word Forms

Derived Forms

• trillionth
  noun

Inflected Forms

Nouns

• trillion
  plural
• trillions
  plural

Etymology

Origin of trillion

1680–90; < French, equivalent to tr ( i )- tri- + ( m ) illion million

Compare meaning

How does trillion compare to similar and commonly confused words? Explore the most common comparisons:

• billion vs. trillion

Explanation

A trillion is 1,000,000,000,000, also known as 10 to the 12th power, or one million million. It’s such a large number it’s hard to get your head around it, so sometimes trillion just means “wow, a lot.” A trillion is bigger than a million, more than a billion, it’s 1,000,000,000,000 (and even or 1,000,000,000,000,000,000 in some countries). (Yes, those are 18 zeroes in that last one.) Either way, this is such a large number that it's hard to imagine. Maybe that's why people often use this word in a looser sense, as in "I have a trillion reasons why I like this band!" That meaning is similar to gazillion, bazillion, and zillion, which aren't real numbers.

Example Sentences

According to the researchers, these reorganized surfaces reduce oxygen reactions by a factor of a billion to a trillion.

From Science Daily • Jul. 12, 2026

Investors piled into exchange-traded funds in the U.S. at a record pace in the first half, with just over $1 trillion in inflows through the end of June, new data showed.

From The Wall Street Journal • Jul. 10, 2026

In 2027, AI capex could top $1 trillion after around $700 billion in 2026 and on top of this the hyperscalers also have off-balance sheet commitments that the market doesn’t quite appreciate yet.

From MarketWatch • Jul. 10, 2026

Beyond the two potential blockbuster listings — Anthropic and OpenAI, each valued around $1 trillion — the IPO pipeline is thin.

From Los Angeles Times • Jul. 10, 2026

There are something like a hundred trillion, 1014, such connections in the human cerebral cortex.

From "Cosmos" by Carl Sagan