Othello: Iago - "O, beware, my lord, of Jealousy" This essay is about William Shakespeare's Othello. It focuses on Iago's words to Othello, “O, beware, my lord, of Jealousy. It is the green-eyed monster.” in act 3, scene 3 and just how important this warning was not only for Othello, but also for Roderigo and for Iago. Before considering the importance of Iago's words, it is important to define what jealousy means. According to The New Lexicon Webster's Encylopedic Dictionary of the English Language, “jealousy is a state of fear, suspicion, revenge or envy caused by a real or imagined threat or challenge to one