Head on damp cloth for pain in the neck (4)
I believe the answer is:
drag
'pain in the neck' is the definition.
(I've seen this in another clue)
'head on damp cloth' is the wordplay.
'head on damp' becomes 'd' (I can't justify this - if you can you should believe this answer much more).
'cloth' becomes 'rag' (rag is a kind of cloth).
'd'+'rag'='DRAG'
'for' is the link.
(Other definitions for drag that I've seen before include "boring experience" , "Pull along with effort" , "Haul - a bore!" , "What female impersonators assume" , "Hunt without foxes" .)