Attack making fool suffer (6)
I believe the answer is:
assail
'attack' is the definition.
(I know that attack can be written as assail)
'fool suffer' is the wordplay.
'fool' becomes 'ass' (both can mean a stupid person).
'suffer' becomes 'ail' (ailing is a kind of suffering).
'ass'+'ail'='ASSAIL'
'making' is the link.
(Other definitions for assail that I've seen before include "Go for" , "Beset" , "Sudden attack" , "storm" , "Slate" .)