Noun

1. the process of making something square; squaring
2. the process of constructing a square having the same area as a given plane figure, or of computing that area
3. a situation in which three celestial bodies form a right-angled triangle, the observer being located at the right angle

   When the Moon is in quadrature, it appears in the sky as a half-moon.

4. the condition in which the phase angle between two alternating quantities is 90°