mess (something) up

1. to break, damage, or spoil something.

She worries that X-rays could mess up her laptop's hard drive.

I messed up my ankle playing touch football.

Most of kids at the party were well behaved, but there's always a few who mess things up.

2. to do something badly or make mistakes.

I really messed up my chemistry exam.

We had a chance to win the game, but we messed it up.

Usage notes: sometimes used in the form mess up on something:

I messed up on my driving test.

• now you're talking
• number cruncher
• number crunching
• number is up
• number one
• numbers game
• nuts and bolts
• nutty as a fruitcake
• occur to
• occur to you
• odd man out
• odd one out
• odds and ends
• of a certain age
• of all people
• of all places
• of all things
• of a mind to
• of a mind to do something
• of a piece
• of a sort
• of course
• of dreams
• off agenda
• off and running