Metric

# Metric

WordNet

(1)   The rhythmic arrangement of syllables
(2)   Based on the meter as a standard of measurement
"The metric system"
"Metrical equivalents"

### noun

(3)   A system of related measures that facilitates the quantification of some particular characteristic
(4)   A decimal unit of measurement of the metric system (based on meters and kilograms and seconds)
"Convert all the measurements to metric units"
"It is easier to work in metric"
(5)   A function of a topological space that gives, for any two points in the space, a value equal to the distance between them
Wiktonary

### Etymology

From métrique (1864) < < ; see meter.

2. A measurement of the "distance" between two points in some metric space: it is a function d(x,y) between points x and y satisfying the following properties: (1) "positive definiteness": $d\left(x,y\right) \ge 0$ and $d\left(x,y\right) = 0 \mbox\left\{ iff \right\} x=y$, (2) "symmetry": $d\left(x,y\right) = d\left(y,x\right)$, and (3) "triangle inequality": $d\left(x,y\right) \le d\left(x,z\right) + d\left(z,y\right)$.