Elbow joint (8)
I believe the answer is:
shoulder
I believe this is a double definition.
'elbow' is the first definition.
(thesaurus)
'joint' is the second definition.
(shoulder is a kind of joint)
(Other definitions for shoulder that I've seen before include "Undertake (burden)" , "Body part of a strange old usher" , "On the side of the road, it might be hard" , "Between the neck and the upper arm (8)" , "Upper body joint" .)