Russia's Yeltsin
I believe the answer is:
boris
'russia's yeltsin' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for boris that I've seen before include "Pasternak, perhaps" , "Russian name" , "- Godunov, Mussorgsky opera" , "Leading Brexiteer's given name" , "-- Godunov; -- Johnson" .)