Monograph isn't about pronoun (3)
I believe the answer is:
his
'pronoun' is the definition.
(I've seen this in another clue)
'monograph isn't about' is the wordplay.
'about' says the answer is hidden in the clue (the clue goes around or about the answer).
'HIS' is hidden in the letters of 'monograph isnt'.
(Other definitions for his that I've seen before include "Belonging to that man" , "that chap's" , "To - Coy Mistress (Marvell)" , "That man's" , "It belongs to him" .)