Astronomical term for a configuration where two celestial bodies have an angular separation of 90 degrees.
When the moon is in quadrature, the angle between the sun and the moon is about 90 degrees.
Rare term for a carpenter's square; the more common reading is かね. See 矩 (かね).
See also: 矩 (かね)
The term 矩 (く) for a carpenter's square is rarely used nowadays.
quadrature
standard; criterion; rule; norm · compass and ruler
square wave; rectangular wave
The kanji 矩 originally depicts a carpenter's square. The reading く is the on'yomi and appears in technical astronomical contexts.