thousandth

American  

[thou-zuhndth, -zuhntth, -zuhnth] / ˈθaʊ zəndθ, -zəntθ, -zənθ /

adjective

1. last in order of a series of a thousand.

2. being one of a thousand equal parts.

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noun

thousandths plural

1. a thousandth part, especially of one (1/1000).

2. the thousandth member of a series.

3. Also thousandth's place (in decimal notation) the position of the third digit to the right of the decimal point.

thousandth British  

/ ˈθaʊzənθ /

adjective

1. (usually prenominal)

   1. being the ordinal number of 1000 in numbering or counting order, position, time, etc

   2. ( as noun )

      the thousandth in succession

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noun

1. 1. one of 1000 approximately equal parts of something

   2. ( as modifier )

      a thousandth part

2. one of 1000 equal divisions of a particular scientific quantity

   millivolt

3. the fraction equal to one divided by 1000 ( 1/ 1000 )

Other Word Forms

Noun Inflected Forms

• thousandths
  plural

Etymology

Origin of thousandth

First recorded in 1545–55; thousand + -th ²

Example Sentences

See Examples For:

thousandth thousandths

In this environment, the sediment layer grows at a rate of just one thousandth of a millimeter per year.

From Science Daily ● Feb. 2, 2026

Any parent who has read a “Berenstain Bears” book aloud under duress for the thousandth time will know what I mean.

From The Wall Street Journal ● Dec. 12, 2025

He was gifted with a superhuman taste sensitivity: He could easily distinguish a flavor at one ten thousandth of a gram in a fifteen ton batch.

From Salon ● Nov. 7, 2024

A millisecond is a thousandth of a second.

From BBC ● Jul. 22, 2024

And for the hundredth time, or maybe the thousandth, I don’t have any answer.

From "The One and Only Ivan" by Katherine Applegate

That yielded speed improvements measured in milliseconds—or thousandths of a second.

From The Wall Street Journal ● Dec. 16, 2025

"It can see things on the scale of a few thousandths of a millimetre," explained Adrian Mancuso, director of physical sciences at Diamond.

From BBC ● Feb. 5, 2025

Back then, Britain’s Allan Wells narrowly beat Silvio Leonard in an era when timing didn’t go down into the thousandths of a second.

From Los Angeles Times ● Aug. 4, 2024

Because of the simplicity of the 128-bit microchip, the robot runs on a mere 75 nanowatts—a couple thousandths as much power as is consumed by a modern pacemaker.

From Science Magazine ● Mar. 7, 2024

His design called for “a hundred or so pieces,” he explained, “which had to fit together to within a precision of a few thousandths of an inch.”

From "Bomb" by Steve Sheinkin