Dimension
in algebra, a literal factor of a product or term; also called a degree; thus ab is an expression of three dimensions. A simple equation is said to be of one dimension. A quadratic of two, a cubic of three, and so on. In geometry, extension in a single line or direction. A line is extended in one direction, or has one dimension, that is length; a surface is extended in two directions, or has two dimensions, length and breadth; a solid is extended in three directions, or has three dimensions, length, breadth, and height or thickness.