quadrant: Meaning and Definition of

quad•rant

1. a quarter of a circle; an arc of 90°.
2. the area included between such an arc and two radii drawn one to each extremity.
3. something shaped like a quarter of a circle, as a part of a machine.
4. one of the four parts into which a plane, as the face of a heavenly body, is divided by two perpendicular lines, numbered counterclockwise from upper right: the first quadrant of the moon.
5. an instrument, usually containing a graduated arc of 90°, used in astronomy, navigation, etc., for measuring altitudes.
6. one of the four quarters of the horoscope: determined by the ascendant, nadir, descendant, and midheaven and numbered counterclockwise from the ascendant.
7. one of two metal sliding pieces, of quadrant form, used to support the fall front of a desk from above.