"The Astronomer-Poet of Persia" (4)

I believe the answer is:
omar
(Other definitions for omar that I've seen before include "Old caliph" , "- Sharif, film actor" , "Arab" , "- - Sharif (films)" , "and 16 Down: Persian poet" .)
I believe the answer is:
omar
(Other definitions for omar that I've seen before include "Old caliph" , "- Sharif, film actor" , "Arab" , "- - Sharif (films)" , "and 16 Down: Persian poet" .)