1. To attack or compete against someone in a very strong or forceful manner. Wow, Jim really socked it to that guy. I didn't know he was that tough! Sock it to them, guys! I know you can beat them!

2. By extension, to deliver news or information to someone that will have a very large impact or effect. A: "I don't think you're going to like these financial results." B: "Sock it to me, I'm ready."