- Screwing up a big project is an example of a fuckup.
- A person who gets arrested all the time and can't hold a job is an example of a fuckup.
The definition of a fuckup is slang for a major mistake or slang for a person who is a major slacker who makes a lot of bad decisions and does nothing good with his life.
Slang a person who habitually bungles or blunders: somewhat vulgar
- One who acts carelessly or foolishly; a bungler.
- A blunder; a bungle.