millionth

American  

[mil-yuhnth] / ˈmɪl jənθ /

adjective

1. coming last in a series of a million.

2. being one of a million equal parts.

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noun

1. the millionth member of a series.

2. a millionth part, especially of one (1/1,000,000).

millionth British  

/ ˈmɪljənθ /

noun

1. 1. one of 1 000 000 approximately equal parts of something

   2. ( as modifier )

      a millionth part

2. one of 1 000 000 equal divisions of a particular scientific quantity

3. the fraction equal to one divided by 1 000 000

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adjective

1. (usually prenominal)

   1. being the ordinal number of 1 000 000 in numbering or counting order, etc

   2. ( as noun )

      the millionth to be manufactured

Etymology

Origin of millionth

First recorded in 1665–75; million + -th ²

Example Sentences

See Examples For:

millionth

When a nuclear weapon detonates or a serious reactor accident occurs, an immense burst of energy is released in less than a millionth of a second.

From Science Daily ● Jun. 3, 2026

When “Swinging Party,” by the Replacements, came on my shuffle for the millionth time, I knew I had to do something different.

From Slate ● Apr. 12, 2026

This year, Amazon deployed its millionth robot, and treated the fleet to a new data model that improved travel time by 10%.

From Barron's ● Nov. 26, 2025

Garcia: Much like you, it’s those small moments like Ozzy screaming, “SHAROOOONNNN!” for the millionth time when he needs a hand or can’t figure something out.

From Los Angeles Times ● Jul. 22, 2025

The nucleus of an atom is tiny–only one millionth of a billionth of the full volume of the atom–but fantastically dense, since it contains virtually all the atom’s mass.

From "A Short History of Nearly Everything" by Bill Bryson