**Car*te"sian** (?), a. [From Renatus *Cartesius*, Latinized from of René *Descartes*: cf. F. *cart'esien*.]

Of or pertaining to the French philosopher René Descartes, or his philosophy.

The **Cartesian** argument for reality of matter.
*Sir W. Hamilton.*

Cartesian coordinates Geom, distance of a point from lines or planes; -- used in a system of representing geometric quantities, invented by Descartes. -- Cartesian devil, a small hollow glass figure, used in connection with a jar of water having an elastic top, to illustrate the effect of the compression or expansion of air in changing the specific gravity of bodies. -- Cartesion oval Geom., a curve such that, for any point of the curve mr + m'r' = c, where *r* and *r'* are the distances of the point from the two foci and *m*, *m'* and *c* are constant; -- used by Descartes.

© Webster 1913.

**Car*te"sian**, n.

An adherent of Descartes.

© Webster 1913.