Sports official (6)
(Other definitions for umpire that I've seen before include "One enforcing the rules in games" , "Game judge" , "Football official" , "Impure (anag) - adjudicator" , "Sports arbiter" .)
'sports official' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for referee that I've seen before include "Arbiter" , "Umpire; arbitrator" , "Sporting arbitrator" , "Sports official" , "Game official" .)