Crum up phrasal verb slang
To spoil or ruin something; to mess something up
He completely crummed up the interview.
The bad weather cummed up our plan.
I added too much salt to the sauce and crummed it up.
My niece crummed my room up with her toys.
To interfere somebosy's plan or bussiness
To disrupt someone's plan.
Spoil or undermine someone's plans or chances
To spoil something with something else
A terrible disaster or a catastrophe
The verb "crum" must be conjugated according to its tense.
The origin of this phrase is not clear.