Delegate (6)
I believe the answer is:
deputy
'delegate' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for deputy that I've seen before include "Person acting on behalf of another" , "The next in command, replaces boss when necessary" , "Stand-in, delegate" , "One given the power to act for another" , "Substitute eg for sheriff" .)