messes up; messed up; messing up
informal
1 : to make a mistake : to do something incorrectly
About halfway into the recipe, I realized that I had messed up, and I had to start over.
— often followed by on
She’s afraid she’ll mess up on the test.
I messed up on my first attempt.
2 a mess (something) up or mess up (something) : to make mistakes when you are doing or making (something)
2 b mess (something) up or mess up (something) : to make (something) dirty or untidy : to make a mess of (something)
Don’t mess up my room
The wind messed up her hair. = Her hair got messed up in the wind.
2 c mess (something) up or mess up (something) : 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 [=has not worked properly] ever since I dropped it in the sink.
The mountains messed up the cell phone signal.
3 a mess (someone) up or mess up (someone) US : to beat and injure (someone)
He got messed up [=roughed up, beaten up] by a gang of bullies.
They messed him up pretty badly.
3 b mess (someone) up or mess up (someone) : 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.