Winter Palace resident (4)
I believe the answer is:
czar
'winter palace resident' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for czar that I've seen before include "Russian ruler (alt. but not rare spelling)" , "Russian emperor" , "person of great power" , "Despot" , "Pre-1917 Russian ruler" .)