from The American Heritage® Dictionary of the English Language, 4th Edition
- n. Mathematics A circular arc of 90°; one fourth of the circumference of a circle.
- n. Mathematics The plane area bounded by such an arc and two perpendicular radii.
- n. Mathematics Any of the four areas into which a plane is divided by the reference axes in a Cartesian coordinate system, designated first, second, third, and fourth, counting counterclockwise from the area in which both coordinates are positive.
- n. A machine part or other mechanical device that is shaped like a quarter circle.
- n. An early instrument for measuring altitude of celestial bodies, consisting of a 90° graduated arc with a movable radius for measuring angles.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. One of the four sections made by dividing an area with two perpendicular lines.
- n. The four regions of the Cartesian plane bounded by the x-axis and y-axis.
- n. One fourth of a circle or disc; a sector with an angle of 90°.
- n. A measuring device with a graduated arc of 90° used in locating an altitude.
from the GNU version of the Collaborative International Dictionary of English
- 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 coördinate 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.
from The Century Dictionary and Cyclopedia
- n. The fourth part; the quarter.
- n. The quarter of a circle; the arc of a circle containing 90°; also, the figure included between this arc and two radii drawn from the center to each extremity; the division of angular magnitude from zero to a right angle, or 90°.
- n. An astronomical instrument for measuring altitudes, of ancient origin, and consisting of a graduated arc of 90°, with a movable radius carrying sights, or the quadrant, carrying sights, might turn about a fixed radius.
- n. An instrument of navigation, for measuring the altitude of the sun, distinctively called the reflecting quadrant.
- n. An instrument used in giving a cannon or mortar the angle of elevation necessary to the desired range.
- n. In electricity, a name suggested for the practical unit of self-induction. Its value is 10 centimeters.
- Four-sided; square.
- n. In embryology, one of the four blastomeres or cleavage-cells in the four-cell stage of the ovum.
- n. A square or one of its sides.
- n. An oscillating arm attached to a spinning-mule to give a proper rotation to the spindles during the winding of the yarn on the cop.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. a measuring instrument for measuring altitude of heavenly bodies
- n. a quarter of the circumference of a circle
- n. the area enclosed by two perpendicular radii of a circle
- n. any of the four areas into which a plane is divided by two orthogonal coordinate axes
Middle English, quarter of a day, from Latin quadrāns, quadrant-, a fourth part; see kwetwer- in Indo-European roots.(American Heritage® Dictionary of the English Language, Fourth Edition)
From Latin quadrantem, accusative singular of quadrāns ("fourth part of something, quarter"). (Wiktionary)