Terrible Russian ruler? (4)
I believe the answer is:
ivan
'terrible russian ruler' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for ivan that I've seen before include "One Day in the Life of - Denisovich (Solzhenitsyn)" , "Russian, say" , "- - the Terrible (Czar)" , "Fellow" , "A Russian emperor, quite Terrible" .)