Foul setter raises cat (4-2)
I believe the answer is:
mess-up
'foul' is the definition.
(thesaurus)
'setter raises cat' is the wordplay.
'setter' becomes 'me' (the setter of the clue).
'raises' says the letters should be written backwards.
'cat' becomes 'puss' (puss is a kind of cat).
'puss' in reverse letter order is 'ssup'.
'me'+'ssup'='MESS-UP'
(Other definitions for mess-up that I've seen before include "Botch" , "Handle (something) ineptly" , "Go wrong -- create disorder" , "Muddle, bungle" , "Ruin" .)