1 a straight line between the centre of a circle and any point on its outer edge; the length of this line
compareDIAMETER
2 a circular area that covers the distance mentioned from a central point:
They deliver to within a 5-mile radius of the store. * Doctors wish to examine everyone living within a 10-mile radius of the factory.
3 (anatomy) the shorter bone of the two bones in the lower part of the arm between the elbow and the wrist, on the same side as the thumb
seealsoULNA
