approximation

American  

[uh-prok-suh-mey-shuhn] / əˌprɒk səˈmeɪ ʃən /

noun

1. a guess or estimate.

   Ninety-three million miles is an approximation of the distance of the earth from the sun.

2. nearness in space, position, degree, or relation; proximity; closeness.

3. Mathematics, Physics. a result that is not necessarily exact, but is within the limits of accuracy required for a given purpose.

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approximation British  

/ əˌprɒksɪˈmeɪʃən /

noun

1. the process or result of making a rough calculation, estimate, or guess

   he based his conclusion on his own approximation of the fuel consumption

2. an imprecise or unreliable record or version

   an approximation of what really happened

3. maths an inexact number, relationship, or theory that is sufficiently accurate for a specific purpose

4. maths

   1. an estimate of the value of some quantity to a desired degree of accuracy

   2. an expression in simpler terms than a given expression which approximates to it

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Other Word Forms

• approximative
  adjective

Etymology

Origin of approximation

1400–50; late Middle English approximacioun (< Middle French ) < Medieval Latin approximātiōn-, stem of approximātiō. See approximate, -ion

Explanation

An approximation is a rough estimate or guess at something. When you write a budget for the month, you're making an approximation of how much you're going to spend. You can't be certain of the exact amount. Like approximately or proximity, approximation comes from the Latin proximus which means "nearest." An approximation is the nearest estimate you can get without having the precise size or measure of something. It's a ballpark figure. When you set out for work in the morning, the amount of time you give yourself to get there is an approximation. Depending on traffic and weather, you can never know exactly how long the trip will take.

Example Sentences

See Examples For:

approximation

Warsh called that measure a “rough swag” or inelegant approximation because it leaves in too many other one-off distortions.

From The Wall Street Journal ● May 31, 2026

The irony of the Daily Wire’s historical excursion is that Walsh has stumbled into an approximation of the very historical critique that critical race theorists have advanced for decades.

From Salon ● May 20, 2026

"This phenomenon was expected by some but now we have a precise approximation for it which didn't exist previously."

From Science Daily ● Apr. 23, 2026

In the Galacticoaster, for instance, riders will build a virtual approximation of a spaceship from a touchscreen, selecting options for wings, cannons and more.

From Los Angeles Times ● Mar. 6, 2026

The most popular game for boys was thinti, and like most boys’ games it was a youthful approximation of war.

From "Long Walk to Freedom" by Nelson Mandela