screw up1
1(Of the muscles of one’s face or around one’s eyes) contract, typically so as to express emotion or because of bright light: his freckled face screwed up with childish annoyance...
- They sat in the shade, their weather beaten faces screwed up against the harsh light.
- He started when he looked down to see a red, puckered face, screwed up in a scowl while staring up at him.
- Mr Black's wrinkly face screwed up to such a degree that he looked like a sun dried tomato.
2 informal, chiefly North American Completely mismanage or mishandle a situation: I’m sorry, Susan, I screwed up...
- In any other situation, if an employee screws up, they get fired.
- For most of my life, I've been in situations where people expect me to screw up.
- What I love is when the accountant screws up on a simple piece of multiplication.
See parent entry: screw
screw-up2 
noun informal, chiefly North American
A situation that has been completely mismanaged or mishandled: a massive bureaucratic screw-up...
- With new people doing new tasks, there are going to be screw-ups, mistakes, confusion, and missteps - one hopes they won't be fatal.
- Sources and methods should not be used as cover for screw-ups and mistakes - which has too often happened in past intelligence scandals.
- The result has been a cascading series of intelligence failures and screw-ups that have hurt the country.