mess up

verb messes up · messing up · messed up

1. transitive To make a mess of; to untidy, disorder, soil, or muss. The afternoon breeze messed up my hair.
2. transitive To cause a problem with; to introduce an error or mistake in; to make muddled or confused; spoil; ruin. The change messed something up, and it's not working anymore.
3. transitive To botch, bungle; to perform poorly on. Well, I messed up my solo, but otherwise it was a good concert.
4. intransitive To make a mistake; to do something incorrectly; to perform poorly. He has a hard time getting started because he's afraid he'll mess up.
5. transitive To cause (another person) to make unwanted mistakes in a given task, usually through distraction or obnoxious behavior. Stop bumping me! You keep messing me up!
6. transitive To damage; injure. He messed up his elbow at the track meet.
7. slang, transitive To manhandle; beat up; rough up. Her brother's friends messed him up a little after he cheated on her.
8. slang, transitive To discombobulate, utterly confuse, or confound psychologically; to throw into a state of mental disarray. That girl totally messed me up, man. I'm not sure who I am anymore.