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