Type of brandy Republican kept in raincoat (4)
I believe the answer is:
marc
'type of brandy' is the definition.
(I've seen this before)
'republican kept in raincoat' is the wordplay.
'republican' becomes 'r' (abbreviation).
'kept in' indicates putting letters inside.
'raincoat' becomes 'mac' (mac is a kind of raincoat).
'r' put into 'mac' is 'MARC'.
(Other definitions for marc that I've seen before include "Type of eau-de-vie made from residue of grapes" , "Strong liquor" , "A brandy; --- Chagall, artist" , "Sort of brandy made from the remains of pressed grapes" , "Grape refuse" .)