Quadrant

One of the four regions of the Plane defined by the four possible combinations of Signs $(+, +)$, $(+,-)$, $(-,+)$, and $(-,-)$ for $(x,y)$.

See also Octant, x-Axis, y-Axis

References

Courant, R. and Robbins, H. What is Mathematics?: An Elementary Approach to Ideas and Methods, 2nd ed. Oxford, England: Oxford University Press, p. 73, 1996.