Attacker makes idiot suffer before worker (9)
I believe the answer is:
assailant
'attacker' is the definition.
(I know that attacker can be written as assailant)
'idiot suffer before worker' is the wordplay.
'idiot' becomes 'ass' (both can mean a stupid person).
'suffer' becomes 'ail' (ailing is a kind of suffering).
'before' says to put letters next to each other.
'worker' becomes 'ant' (worker is a type of ant).
'ass'+'ail'+'ant'='ASSAILANT'
'makes' acts as a link.
(Other definitions for assailant that I've seen before include "An attacker like mugger" , "Aggressor" , "Who would tear into" , "who is on the offensive?" , "One attacking another" .)