Mahershala of "Green Book” (3)
I believe the answer is:
ali
'mahershala of green book' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for ali that I've seen before include "Fourth caliph of Islam" , "Mohammed . . . (boxer)" , "Muhammad ... (former fighter)" , "Egyptian name" , "Muhammad - - , legendary boxer" .)