Quadrature
the state of being quadrate or square; a square space. In astronomy, the position of one heavenly body with respect to another 90° dista tant, as the moon when midway between the points of opposition and conjunction.
In geometry, the act of squaring; the reducing of a figure to a square. The quadrature of the circle is a famous problem, which has probably been the subject of more discussion and research than any other problem within the whole range of mathematical science.