Bone of the upper arm (7)
I believe the answer is:
humerus
'bone of the upper arm' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for humerus that I've seen before include "Arm bone (that sounds comical)" , "What's often thought funny" , "Bone that sounds funny?" , "Arm bone - the "funny bone"" , "Upper arm bone" .)