Othello schemer (4)
I believe the answer is:
iago
'othello schemer' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for iago that I've seen before include "Evil character in Othello" , "The villain who tricked Othello" , "Shakespeare's jealous villain" , "Othello's evil counsellor" , "villainous ensign" .)