Elbow or knee (5)
I believe the answer is:
joint
I believe this clue is a double definition.
'elbow' is the first definition.
(thesaurus)
'knee' is the second definition.
(I've seen this in another clue)
(Other definitions for joint that I've seen before include "Piece of meat - illegal smoke" , "Shared, held in common" , "cigarette with grass" , "Combined" , "Bone junction" .)