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

Census Approximation Bureau: The government’s plan to save billions by hiring one guy to browse Google Maps on an iPhone.

From Washington Post • Jul. 7, 2016

Figure 1.23 Approximation of a curve by line segments.

From Textbooks • Mar. 30, 2016

Figure 7.23 Approximation of a curve by line segments.

From Textbooks • Mar. 30, 2016

Approximation and a sense of small numbers, while critical, are not enough for humans to precisely grasp large numbers, he says.

From Nature • Jan. 9, 2013

Approximation to surface in the symmetrical forms. b.

From Froebel's Gifts by Wiggin, Kate Douglas Smith