Definitions of quadrant

  1. the area enclosed by two perpendicular radii of a circle
  2. any of the four areas into which a plane is divided by two orthogonal coordinate axes
  3. a quarter of the circumference of a circle
  4. The fourth part; the quarter.
  5. The quarter of a circle, or of the circumference of a circle, an arc of 90¡, or one subtending a right angle at the center.
  6. One of the four parts into which a plane is divided by the coordinate axes. The upper right- hand part is the first quadrant; the upper left- hand part the second; the lower left- hand part the third; and the lower right- hand part the fourth quadrant.
  7. An instrument for measuring altitudes, variously constructed and mounted for different specific uses in astronomy, surveying, gunnery, etc., consisting commonly of a graduated arc of 90¡, with an index or vernier, and either plain or telescopic sights, and usually having a plumb line or spirit level for fixing the vertical or horizontal direction.
  8. One- fourth of a circle, or an arc of 90 degrees; an instrument for measuring heights; an instrument for raising a cannon to the height needed for the desired range.
  9. ( geom.) The fourth part of a circle, or an arc of 90°: an instrument consisting of the quadrant of a circle graduated in degrees, used for taking altitudes.
  10. Quarter of a circle; arc of 90°; instrument for taking altitudes.
  11. The quarter of a circle, or of its circumference.
  12. The quarter of a circle, or an arc of 90; an instrument for taking altitudes; an instrument used for elevating cannon. Quadrant of altitude, a thin pliable strip of brass belonging to an artificial globe.
  13. In geom., the quarter of a circle; an arc of 90°; in nav. and astron., an instr. for taking elevations, adapted for measuring an arc of not more than 90°.
  14. Quadrantal.