Attack gives fool trouble (6)
I believe the answer is:
assail
'attack' is the definition.
(I know that attack can be written as assail)
'fool trouble' is the wordplay.
'fool' becomes 'ass' (both can mean a stupid person).
'trouble' becomes 'ail' (synonyms).
'ass'+'ail'='ASSAIL'
'gives' is the link.
(Other definitions for assail that I've seen before include "Sudden attack" , "Slate" , "Criticise severely" , "Maybe mug" , "Set upon" .)