An Etymological Dictionary of Astronomy and Astrophysics

1. A mathematical → expression consisting of an → array of → components which are needed for calculating → infinitesimally small → distances between two → points in some geometrical → space. More simply put, the → function used to define a distance between two points in a → metric space. Also called → distance function.
   

2. In → general relativity the metric describes the → space-time geometry and gives the interval between two neighboring → events.
   

3. Pertaining to the meter or to the → metric system.

See also: From → meter + → -ic.