in mathematics, the process of finding a square equal in area to a given surface or figure
in astronomy, a configuration in which two celestial bodies form an angle of 90° with a third body, esp the earth
in electronics, a phase difference of one quarter cycle or 90° between two waves, e.g. the current and voltage in an alternating current
[Latin quadratura square, act of squaring, from quadrare: see quadrate1]