A commonly used map projection that uses a set of transverse mercator projections for the globe which are divided into 60 zones, each covering 6 degrees longitude. Each zone has an origin of the central meridian and latitude of 0 degrees.
Definition adapted from: URL: http://www.agriculture.purdue.edu/SSMC/Frames/newglossery.htm
For more, visit the Wikipedia entry for UTM, URL: http://en.wikipedia.org/wiki/Universal_Transverse_Mercator_coordinate_system