Grief, pint being spilt in joint (9)
I believe the answer is:
fingertip
'joint' is the definition.
The answer and definition can be both body parts as well as being singular nouns.
Perhaps they are linked in a way I don't understand?
'grief pint being spilt' is the wordplay.
'being spilt' indicates anagramming the letters.
'grief'+'pint'='griefpint'
'griefpint' anagrammed gives 'FINGERTIP'.
'in' is the link.
Can you help me to learn more?
(Other definitions for fingertip that I've seen before include "One's used to feel" , "at which things are very familiar" , "One of the points" , "Digital extremity" , "Pointer" .)