“Green eyed monster” is an idiom for jealousy. It often suggests a strong, unhealthy jealousy that changes how a person thinks and acts. In modern English, people use it for romantic jealousy, but it can also describe envy of another person’s success or attention.
The phrase comes from Shakespeare’s Othello. In the play, jealousy grows until it destroys trust and leads to tragedy. That is the key link to the modern meaning: the emotion is pictured as a monster because it can take control of someone and cause damage.
You may also notice that English distinguishes jealousy and envy, but everyday use sometimes overlaps. Jealousy is often fear of losing something, such as love or attention. Envy is wanting what someone else has. Even so, “green eyed monster” is commonly understood as jealousy in a broad sense.
- After hearing about his coworker’s promotion, the green eyed monster appeared.
- In the play, the green eyed monster destroys Othello’s judgment.
Because the phrase is vivid and literary, it is more common in expressive writing and speech than in very formal communication.