quadrature — ONAD

quadrature /ˈkwädrəCHər, ˈkwɑdrətʃər

▸ noun

1 Mathematics the process of constructing a square with an area equal to that of a circle, or of another figure bounded by a curve.

2 Astronomy the position of the moon or a planet when it is 90° from the sun as viewed from the earth.

3 Electronics a phase difference of 90° between two waves of the same frequency, as in the color difference signals of a television screen.

– ORIGIN mid 16th century (as a mathematical term): from Latin quadratura ‘a square, squaring’, from quadrare (see quadrate).