Pronunciation: (u-prok"su-mā'shun),[key] —n. 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. Math.,Physics.a result that is not necessarily exact, but is within the limits of accuracy required for a given purpose.