**dimension,** in mathematics,
number of parameters or coordinates required to describe points in a mathematical
object (usually geometric). The space we inhabit, having height,
width, and depth, is three-dimensional; a plane or surface is two-dimensional; a line
or curve is one-dimensional; and a point is zero-dimensional. By means of a coordinate
system, e.g. CARTESIAN COORDINATES, one can specify any point
with respect to a chosen origin (and coordinate axes through the origin, in the case
of two or three dimensions). By analogy, and ordered set of four, five, or more
numbers is defined as representing a point in a space of four, five, or more
dimensions.
--*The Concise Columbia Encyclopedia*