in general, denotes any plain surface. The Latin word more properly denoted a threshing floor; and is derived from arere to be dry.

Architecture, denotes the space or site of ground on which an edifice stands. It is also used for inner courts and other inclosed spaces.

in Geometry, denotes the superficial content of any figure. Thus, if a figure, e.g., a field, be in form of a square, and its side be 40 feet long, its area is said to be 1600 square feet; or it contains 1600 little squares, each a foot every way.