Definition of dimension

• n. - Measure in a single line, as length, breadth, height, thickness, or circumference; extension; measurement; -- usually, in the plural, measure in length and breadth, or in length, breadth, and thickness; extent; size; as, the dimensions of a room, or of a ship; the dimensions of a farm, of a kingdom.
• n. - Extent; reach; scope; importance; as, a project of large dimensions.
• n. - The degree of manifoldness of a quantity; as, time is quantity having one dimension; volume has three dimensions, relative to extension.
• n. - A literal factor, as numbered in characterizing a term. The term dimensions forms with the cardinal numbers a phrase equivalent to degree with the ordinal; thus, a2b2c is a term of five dimensions, or of the fifth degree.
• n. - The manifoldness with which the fundamental units of time, length, and mass are involved in determining the units of other physical quantities.