a particular and early map projection in common use especially for navigational maps
A cylindrical map projection devised by Gerardus Mercator in 1569. Its parallels and meridians are straight lines, and the unavoidable east-west stretching away from the equator is accompanied by a corresponding north-south stretching, so that at each location the east-west scale is the same as the north-south-scale.
a map projection of the earth onto a cylinder; areas appear greater the farther they are from the equator