This page is about the slang term louse up
to spoil something or make it fail
- She really wants this job, so I hope she doesn't louse up the interview.
- Don't worry. He won't louse it up. He's been doing these deals for years.
This is typically used in American English but may be used in other varieties of English too.
If Meg louses up this sale, she
Contributor: Matt Errey