metric space

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun mathematics Any space whose elements are points, and between any two of which a non-negative real number can be defined as the distance between the points; an example is Euclidean space

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun a set of points such that for every pair of points there is a nonnegative real number called their distance that is symmetric and satisfies the triangle inequality