Definition from Wiktionary, the free dictionary
Alternative forms 
- (vulgar) An incompetent individual; one who errs frequently.
- He is such a fuck up.
- (vulgar) A severe mistake.
- That fuck up cost us the contract.
One who can never seem to get anything quite right
- (intransitive, slang) To make a mistake, to go wrong
- You really fucked up this time.
- (transitive) To botch or make a mess of
- I fucked up question 3 of the exam.
- (transitive) to injure or damage
- I fucked up my knee while running the marathon.
To make a mistake, to go wrong
To botch or make a mess of
to injure or damage
Usage notes 
This phrase is considered vulgar slang and its use in polite company could be insulting.