global positioning system

Short definition from Wiktionary

Noun

1. 1
   Any system which enables a mobile receiver to determine its precise location based on signals received from satellites such as those of the US military, the Russian GLONASS system, or the proposed Galileo European alternative system.

Proper noun

1. 1
   A system which enables a mobile receiver to determine its precise location based on signals received from a constellation of US military satellites.