Sharif of "Doctor Zhivago” (4)
I believe the answer is:
omar
'sharif of doctor zhivago' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for omar that I've seen before include "- Khayyam, Persian poet, astronomer and mathematician" , "old poet" , "Old caliph" , "- - Sharif (films)" , "- Khayyam, Pers. poet" .)