The crossword solution for the term 'Shakespearean Traitor' is Iago, a four-letter word. Iago is a character from William Shakespeare's play Othello, and is known as one of the Bard's most notorious villains. He is a master manipulator who betrays his friend Othello by convincing him that his wife Desdemona is unfaithful. Iago's treachery ultimately leads to the downfall of Othello and Desdemona.