punch lights out
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punch (one's) lights out
To render someone unconscious with a punch. A: "Oh man, what happened?" B: "Well, you and Bart were fighting, and then Bart punched your lights out." Wow, you're strong—you could punch someone's lights out no problem!
punch someone's lights out
Sl. to knock someone out with a fist. You had better stop that, or I will punch your lights out! Do you want me to punch your lights out?