noun

• 1technical Each of four quarters of a circle.

  1. 1.1Each of four parts of a plane, sphere, space, or body divided by two lines or planes at right angles.
     More example sentences

     • ‘the right upper quadrant of the kidney’

• 2historical An instrument used for taking angular measurements of altitude in astronomy and navigation, typically consisting of a graduated quarter circle and a sighting mechanism.

• 3A frame fixed to the head of a ship's rudder, to which the steering mechanism is attached.

  1. 3.1A panel with slots through which a lever is moved to orient or otherwise control a mechanism.