Idiom
louse something up
Theme: RUIN
to mess up or ruin something. (Slang.)I've worked hard on this. Please don't louse it up.You've loused up all my plans.
Slang
louse something up
Theme: FAILURE
tr. to botch something up.Please don't louse the typewriter ribbon up this time.Jack loused up my effort to win approval for my plan.