Translate radius | into French | into German | into Italian | into Spanish
The plural of radius can be spelled either radii (as in the original Latin) or radiuses.
noun (plural radii /ˈrādēˌī/ or radiuses)
- 1a straight line from the center to the circumference of a circle or sphere. See also illustration at geometric.
- 2 Anatomy the thicker and shorter of the two bones in the human forearm. Compare with ulna.
late 16th century (sense 2): from Latin, literally 'staff, spoke, ray'