funny bone, highly sensitive area at the back of the elbow where the ulnar nerve passes close to the surface of the skin in a groove between end prominences of the humerus (the upper arm bone) and the ulna (the large forearm bone). A blow to the area causes the nerve to compress against bone, producing a characteristic tingling in the forearm and the last two fingers.
The Columbia Electronic Encyclopedia, 6th ed. Copyright © 2012, Columbia University Press. All rights reserved.