What does quadrant mean?
A quadrant is one of four parts into which a larger whole may be divided, most commonly a circle, plane, or other geometric figure. In coordinate geometry, the word refers to the four regions formed by two perpendicular axes: the first quadrant has positive x- and y-values, the second negative x- and positive y-values, the third has negative values for both, and the fourth has positive x- and negative y-values. The term also has specialized anatomical uses for regions around the eye and for the four clinical regions of the abdomen. More generally, “every quadrant” can suggest that something has been examined or affected across all parts of a place or system. Although now associated chiefly with geometry and anatomy, quadrant was once also the name of an instrument used to measure the altitude of celestial objects. Its simple underlying idea remains the division of a whole into four corresponding parts.
nounOne of four equal parts into which a circle, plane, surface, or other whole may be divided. In mathematics and geography, a quadrant is also one of the four regions determined by two perpendicular axes.
- Any one of four equal or approximately equal parts into which a whole may be divided.
- One of the four regions into which two perpendicular coordinate axes divide a plane.
- One of the four regions surrounding the centre of the eye.
- One of four anatomical regions into which the abdomen is conventionally divided for clinical description.
- An obsolete instrument formerly used to measure celestial altitude.
"The observatory was positioned in the northern quadrant, away from the glare of the city."
"Their restaurant occupies the eastern quadrant of the city centre."
"A point with positive coordinates lies in the first quadrant of a standard Cartesian plane."
The plural is used when referring to several of the four geometric regions or to separate areas within a larger place.
"Retail activity was concentrated in the eastern and northern quadrants of the city."
Quadrant began with one of geometry's simplest ideas: a circle naturally divides into four equal quarters.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does quadrant come from?
Quadrant entered English in the late 16th century from Latin quadrans, meaning “a fourth part.” Latin quadrans was derived from quartus, “fourth,” which also lies behind the English word quarter. The geometric sense developed from the division of a circle or similar figure into four equal parts. The older sense for an astronomical measuring instrument uses the same term in reference to the quarter-circle graduated on its arc.
Related word forms
How quadrant is actually used
In mathematics, the numbering of quadrants follows the standard Cartesian convention, with the first quadrant in the upper right. Clinical references to abdominal quadrants generally specify right or left and upper or lower. The instrument sense is historical and uncommon in modern English.
Easily confused with quadrant
A quadrant is a geometric region or one of four parts, whereas a quadratic is an algebraic expression involving a squared variable.
A quadrant is a fourth of a larger geometric whole, while a quart is a unit of liquid or dry measure.