- (n.) The fourth part; the quarter.
- (n.) 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.
- (n.) 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.
- (n.) 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.
Webster's Revised Unabridged Dictionary
| APA | Webster's. (2011). quadrant. Retrieved September 20, 2026, from http://smartdefine.org/quadrant/definitions/2051526 |
| Chicago | Webster's. 2011. "quadrant" http://smartdefine.org/quadrant/definitions/2051526 (accessed September 20, 2026). |
| Harvard | Webster's 2011, quadrant, Smart Define, viewed 20 September, 2026, <http://smartdefine.org/quadrant/definitions/2051526>. |
| MLA | Webster's. "quadrant" 27 May 2011. Web. 20 September 2026. <http://smartdefine.org/quadrant/definitions/2051526> |