funny bone

noun3

1. •
   The ulnar nerve in the elbow, which, when hit, causes a tingling sensation.

   • Ouch, I just hit my funny bone.
2. •
   (figurative) One's sense of humor.

   • His wisecracks always tickle my funny bone.
3. •
   Nickname for the humerus, so named because of its being homophonic with "humorous".