Stop umpire having shower (7)
I believe the answer is:
refrain
'stop' is the definition.
(I've seen this before)
'umpire having shower' is the wordplay.
'umpire' becomes 'ref' (short for referee).
'having' is a charade indicator (letters next to each other).
'shower' becomes 'rain' (rainfall).
'ref'+'rain'='REFRAIN'
(Other definitions for refrain that I've seen before include "Desist, abstain" , "Much repeated saying" , "tune" , "Recurring music to forbear from" , "Cease - repeated phrase" .)