louse something up

louse (someone or something) up

To ruin, spoil, mess up, or bungle someone or something. Her sudden decision to quit in the middle of the project really loused us up. I am not letting your crummy attitude louse up my vacation—if you want to be grouch, you can go somewhere else and do it alone!
See also: louse, up

louse something up

tv. to botch something up. Please don’t louse the typewriter ribbon up this time.
See also: louse, something, up