The terrible Russian? (4)
I believe the answer is:
ivan
'the terrible russian?' 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 "Name of six Russian tzars" , "Russian, say" , "__ Lendl, Czech-born American tennis star" , "'Terrible' emperor of Russia" , "Tsar - 197> the Terrible" .)