Pain associated with a knife (5)
I believe the answer is:
panga
'knife' is the definition.
(panga is a kind of knife)
'pain associated with a' is the wordplay.
'pain' becomes 'pang' (pang is a kind of pain).
'associated with' says to put letters next to each other.
'pang'+'a'='PANGA'
(Other definitions for panga that I've seen before include "Heavy knife of East Africa" , "Heavy African knife" , "Deal successfully (with)" , "African machete-like tool" .)