(1) Relating to or based on the metric system. (2) Relating to or arranged in meter.
Example:
Many Americans are beginning to become accustomed to metric units such as the liter, milligram, and kilometer.
The metric system, used in most of the world to measure distance, weight, and volume, is built in part on a unit length called the meter, from which it takes its name. Other metric units are the kilogram (from the basic unit of weight) and liter (the basic unit of volume). Metric can also refer to the meter, or rhythm, in songs and poetry, although the word metrical is used more often for this meaning. So while the scientists' measurements are usually metric, the poets' are usually metrical.