quadrant

American  

[kwod-ruhnt] / ˈkwɒd rənt /

noun

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. Geometry, Astronomy. 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. Astrology. one of the four quarters of the horoscope: determined by the ascendant, nadir, descendant, and midheaven and numbered counterclockwise from the ascendant.

7. Furniture. one of two metal sliding pieces, of quadrant form, used to support the fall front of a desk from above.

---

quadrant British  

/ kwɒˈdræntəl, ˈkwɒdrənt /

noun

1. geometry

   1. a quarter of the circumference of a circle

   2. the area enclosed by two perpendicular radii of a circle and its circumference

   3. any of the four sections into which a plane is divided by two coordinate axes

2. a piece of a mechanism in the form of a quarter circle, esp one used as a cam or a gear sector

3. an instrument formerly used in astronomy and navigation for measuring the altitudes of stars, consisting of a graduated arc of 90° and a sighting mechanism attached to a movable arm

---

quadrant Scientific  

/ kwŏd′rənt /

1. An arc equal to one quarter of the circumference of a circle; an arc of 90°.

2. Any of the four regions into which a plane is divided by the axes of a Cartesian coordinate system. The quadrants are numbered counterclockwise one through four, beginning with the quadrant in which both the x- and y-coordinates are positive (usually the upper right quadrant).

3. A navigational instrument similar to a sextant but with an arc of 90° rather than 60°.

4. See more at sextant

---

Other Word Forms

• quadrantal adjective
• quadrantlike adjective

Etymology

Origin of quadrant

1350–1400; Middle English < Latin quadrant- (stem of quadrāns ) fourth part

Explanation

A quadrant is one-fourth of a circle. When you bake an apple pie and then cut it equally so that you and three of your friends get pieces that are the same size, you'll each get a quadrant of the pie. When a circle is evenly divided into four sections by two perpendicular lines, each of the four areas is a quadrant. In fact, anything that's split into four equal parts can be described as being made up of quadrants, like a quadrant of a public park. The Latin root word is quadrantem, fourth part, and for many years quadrant was used to mean six hours, or one-quarter of a day.

Example Sentences

Argentina and Portugal appear to be the standout teams in the quadrant which will provide their opponents.

From BBC • Dec. 5, 2025

U.S. equities fell from the top-right leading quadrant to the bottom-right weakening quadrant.

From MarketWatch • Nov. 24, 2025

Not one of the 14 pitches he saw from Blue Jays starter Shane Bieber was near the middle quadrant of the plate.

From Los Angeles Times • Oct. 29, 2025

The complicated process involves Maryland taking over control of the track, building a training center and eventually closing Laurel Park to shift full-time racing to Pimlico in the northwest quadrant of Baltimore.

From Seattle Times • May 14, 2024

No major weather disturbance reported that day in quadrant.

From "Life of Pi" by Yann Martel

Related Words

• fourth
• one-fourth
• part
• portion
• term