Othello's false friend (4)
I believe the answer is:
iago
'othello's false friend' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for iago that I've seen before include "Evil character in Othello" , "The villain who tricked Othello" , "Othello's enemy" , "stage villain" , "Othello's treacherous officer" .)