Definition of: Cartesian coordinate system

Geom.
1. A plane system for indicating the curve of an equation graphically by means of two axes, graduated in both directions from the origin: when intersecting at right angles, the coordinates are called rectangular, when intersecting at any angle other than 90°, the coordinates are called oblique.
2. A three-dimensional system for indicating the shape of a solid by means of three planes intersecting at right angles to each other at a point called the origin: from the three points of reference required, any point in space with coordinates x, y, and z can be located. See illustration under OCTANT. Also called rectangular coordinate system.