quadrature Definition

quadrature
noun

1a. math.
The process that involves expressing a given area that is bounded by a curve, eg a circle, as an equivalent square area;
1b. math.
The process of making something square, or of dividing it into squares.
2a. astron.
Either of the two points in space or time where the moon, when it is viewed from the Earth, is 90° distant from the sun;
2b. astron.
Any configuration where two celestial bodies are 90° away from each other.

Etymology: 16c: from Latin quadratura a square or an act of squaring.