Radial

Radial: A word with diverse meanings in medicine and the biomedical sciences: Pertaining to the radius, the smaller bone in the forearm. The radial artery is so named because of its proximity to the radius. Pertaining to the radius of a circle. Spreading from a central point. A radial keratotomy is an eye operation in which incisions are made in the cornea that resemble the spokes in a wheel.

The word "radial" comes from the Latin "radius" meaning a spoke in a wheel which this bone was thought to resemble. The word "radiation" is derived from the same Latin word -- "radius."