One entry found for radius.

Main Entry: ra·di·us
Pronunciation: rd--s
Function: noun
Inflected Form(s): plural ra·dii /-- /; also ra·-di·us·es
Etymology: from Latin radius "ray, beam, spoke" --related to RADIATE, RADIO, ²RAY
1 : the bone on the thumb side of the human forearm; also : a corresponding bone of other vertebrates
2 : a line extending from the center of a circle or sphere to the circumference or surface
3 a : the length of a radius b : a circular area defined by a given radius <deer may wander within a radius of several miles>
4 : a radial part or plane
[radius illustration]

Pronunciation Symbols