Definition of quadrature in English:

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Pronunciation: /ˈkwädrəCHər/


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.
Example sentences
  • Craig published several more papers on the logarithmic curve, the curve of quickest descent and quadrature of figures.
  • He generalised Gauss's method of quadrature and expressed the polynomials which are involved as a determinant.
  • This book is a treatise on infinite series, summation, interpolation and quadrature.
2 Astronomy The position of the moon or a planet when it is 90° from the sun as viewed from the earth.
Example sentences
  • When the Sun-Moon system is in quadrature relative to the Earth, the combined gravitational forces are not as strong.
  • The planet is at east quadrature (ninety degrees east of the Sun) on the 26th.
3 Electronics A phase difference of 90° between two waves of the same frequency, as in the color difference signals of a television screen.
Example sentences
  • The MT312 is a single-chip variable rate digital quadrature phase shift keying satellite demodulator.
  • The L5 signal that will appear with the Block IIF satellites in 2006, will have quadrature phase skip keying.
  • The quadrupolar echo pulse sequence was employed using quadrature detection with complete phase cycling of the pulse pairs.


Mid 16th century (as a mathematical term): from Latin quadratura 'a square, squaring', from quadrare (see quadrate).

For editors and proofreaders

Syllabification: quad·ra·ture

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