mess (something or someone) upidiom
Definition of mess (something or someone) up
: to make mistakes when one is doing or making (something) He messed up the speech. I messed up my first attempt and had to try again.
1 : to make (something) dirty or untidy : to make a mess of (something) Don't mess up my room. The wind messed up her hair.
2 : to damage or ruin (something) She's really messed up her life. His life has been messed up by his drug addiction. : to damage or change (something) so that it does not work properly I don't know what I did, but I somehow messed up the computer. My watch has been messed up ever since I dropped it in the sink. The mountains messed up the cell phone signal.
3 US : to beat and injure (someone) He got messed up by a gang of bullies. They messed him up pretty badly.
4 : to make (someone) very upset and unhappy Breaking up with her boyfriend has really messed her up. She's been pretty messed up ever since she broke up with her boyfriend.