quad|rant

quad|rant «KWOD ruhnt», noun.

1. a) a quarter of the circumference of a circle; arc of 90 degrees. b) the area contained by such an arc and two radii drawn perpendicular to each other.

2. a thing or part shaped like a quarter circle.

3. an instrument with a scale of 90 degrees, used in astronomy, surveying, and navigation for measuring altitudes.

4. Geometry. one of the four parts into which a plane is divided by two straight lines crossing at right angles. The upper right-hand section is the first quadrant, and, in a counterclockwise direction, the others are the second, third, and fourth quadrants respectively.

5. Embryology. one of the four blastomeres in the four-cell stage of the ovum.

╂[< Latin quadrāns, -antis a fourth, related to quattuor four]