Definition of: quadrature

(kwod′rə·chər) noun
1. The act or process of squaring.
2. The finding in square measure of the area of any surface, especially one bounded by a curve.
3. Astron. a The relative position of two heavenly bodies that are 90° apart as viewed from the center of a third body, b Either intersection of an orbit with a line whose ends terminate in the curve drawn perpendicular to the major axis through the focus.