metric

A measure for something; a means of deriving a quantitative measurement or approximation for otherwise qualitative phenomena (especially used in engineering).

(mathematics) A function for the measurement of the "distance" between two points in some metric space: it is a real-valued function d(x,y) between points x and y satisfying the following properties: (1) "non-negativity": d(x,y)>0, (2) "identity of indiscernibles": d(x,y)=0 mbox iffx=y, (3) "symmetry": d(x,y)=d(y,x), and (4) "triangle inequality": d(x,y)<d(x,z)+d(z,y).

(mathematics) A metric tensor.

Abbreviation of metric system.