quadrant

quadrant
/ˈkwɔdrənt; `kwɑdrənt/ n
1 quarter of a circle or of its circumference 圆的或圆周的四分之一; 象限. =>illus at circle 见circle插图.
2 instrument with an arc of 90 marked off in degrees, for measuring angles 象限仪; 四分仪.

牛津英汉双解词典