Slugged In Leo’s company, Jack felt like a lesser version of his older brother. Not as intelligent, interesting, or successful, an identity that had attached to him in high school and had never completely gone away. At the beginning of ninth grade, some of Leo’s friends had christened Jack Leo Lite and the denigrating name stuck, even after Leo graduated. His first month at college, Jack had run into someone from his hometown who had reflexively greeted him by saying, “Hey, Lite. What’s up?” Jack had nearly slugged him. What does "slugged" mean here?