1530s, "vacant piece of ground," from Latin area "level ground, open space," used of building sites, playgrounds, threshing floors, etc.; of uncertain origin. Perhaps related to arere "to become dry," on notion of a burned clearing or dry, bare space. The generic sense of "amount of surface (whether open or not) contained within any set of limits" is from 1845. Area code in North American telephone systems is attested from 1959.