Related Clues:

• Radius' partner
• Bone below a humerus
• Hinge-joint bone
• Outer arm bone
• Bit of careful navigating for one out on a limb, perhaps
• Bone from the centre?
• It comes with a radius of a useful nature
• Bone with a little useful name
• Bone of forearm - distance from centre
• Inner bone of the human forearm
• Half diameter
• Bone - half of diameter
• Half diameter of circle
• Bone of forearm
• Prismatic bone