Support a worker who is accused (9)
I believe the answer is:
defendant
'is accused' is the definition.
(thesaurus)
'support a worker' is the wordplay.
'support' becomes 'defend' (defending is a kind of supporting**).
'a worker' becomes 'ant' (worker is a type of ant).
'defend'+'ant'='DEFENDANT'
'who' acts as a link.
(Other definitions for defendant that I've seen before include "Against whom an action is brought in a law court" , "One charged" , "The one before the court" , "Person accused" .)