Borodin opera prince (4)
I believe the answer is:
igor
'borodin opera prince' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for igor that I've seen before include "-- Stravinsky, composer" , "Prince in Borodin's opera" , "Russian boy" , "Card game" , "Stravinsky's first name" .)