beat the daylights out of
beat the (living) daylights out of (someone)
1. To deliver a violent and prolonged physical attack. Our neighbor is in the hospital because a burglar beat the daylights out of him. I'm worried that the captain of the football team will beat the living daylights out of me if he finds out that I'm secretly seeing his girlfriend. Oh, my boyfriend knows that I would beat the living daylights out of him if he ever lies to me about something that serious.
2. To defeat an opponent decisively. The final score was 17-1? Wow, we really beat the living daylights out of that team!
beat the (living) daylights out ofgive someone a very severe beating. informal
Daylight or daylights has been used from the mid 18th century as a metaphor for ‘eyes’, and here has the extended sense of any vital organ of the body.