fuck it up /ˈfʌk ɪt ʌp/ verb2 •(disapproving, vulgar) To screw up greatly; to make a mistake, usually inviting rude/worried comments from others.Man, you really fucked it up this time.Ooh shit, we really fucked it up this time! •(slang, vulgar) To go at something competently, usually in an aggressive or quick manner.Yeah, Jonas! Fuck it up!! formsfucked it up · fucking it up · fucks it up