Possible Clues:

• It has a humerus side?
• It extends from the elbow
• Funny-bone neighbor
• Leg : fibula :: arm : __
• Bone usually located near adductor initially
• Bone placed in useful napkin
• Bone adjoining the humerus
• Bit of careful navigating for one out on a limb, perhaps
• Outer arm bone
• Radius' partner