The term "funny bone" refers to the ulnar nerve, which runs along the inside of your elbow. When you accidentally hit your elbow in a certain way, you may feel a sudden, sharp tingling or numbness sensation in your forearm, hand, and fingers. This sensation is commonly referred to as hitting your "funny bone," although it's not actually a bone.

Although I think the phrase "funny bone" is a pun on the name "humerus" (i.e. "humorous,"), I agree with Ahmadi Nacer Eddine--it is an area near the elbow where the ulnar nerve is close to the surface. And I personally find the sensation intensely painful, and not funny at all.

Thanks for your input Dan! I agree it’s not funny but it’s not hugely painful such as another part of the body being injured. I do think the pain in the funny bone is different!