Protestant's row in Arabian state (9)
I believe the answer is:
orangeman
'protestant's' is the definition.
(member of a Northern Irish Protestant group)
'row in arabian state' is the wordplay.
'row' becomes 'range' (I've seen this in other clues).
'in' indicates putting letters inside.
'arabian state' becomes 'Oman' (Oman is a Middle Eastern country).
'range' placed inside 'oman' is 'ORANGEMAN'.
(Other definitions for orangeman that I've seen before include "one used to marching?" , "Northern Ireland Protestant" , "Religious society member" , "Member of a Protestant Irish society" .)