Metes and Bounds -- Description of land by boundary lines, with their terminal points and angles. Originally metes referred to distance, bounds to direction; contemporarily, the words have no individual meaning of practical significance.

http://westerndivision.ctt.com/sistersites/santa_barbara/terms.htm#M

Edit: In states that have been laid out by government survey into sections and townships, land-parcels can be described on the basis of those units; for example: "the south 200 feet of the east half or the north-east quarter" of section thus-and-so. This is refered to as the government survey system or, more technically, the cadastral system.

Irregular tracts will however require a metes and bounds description (or a description by reference to a plat or may depicting the dimensions and position of various tracts).