Also found in: Dictionary, Thesaurus, Medical, Legal, Acronyms, Encyclopedia, Wikipedia.
To mess up or ruin something. The threat of a hurricane really fouled up our vacation plans! Boy, you really fouled up this report, and I don't have time to fix it right now.
foul someone or something up
to cause disorder and confusion for someone or something; to tangle up someone or something; to mess someone or something up. Go away! Don't foul me up any more. You've fouled up my whole day. Watch out! You're going to foul up my kite strings.
to blunder; to mess up. Please don't foul up this time. The quarterback fouled up in the first quarter, and that lost us the game.
messed up; ruined; tangled up. (Usually as fouled-up when attributive.) This is sure a fouled-up mess. You sure are fouled up, you know.
Blunder or cause to blunder; botch, ruin. For example, He's fouled up this report, but I think we can fix it, or Our plans were fouled up by the bad weather. This expression is widely believed to have originated as a euphemism for fuck up. [Colloquial; c. 1940]
1. To blunder because of mistakes or poor judgment: I've tried many times to pass this test, but this time I really fouled up.
2. To cause someone or something to blunder: The howling dogs distracted me and fouled up my concentration. The pain in my hand fouled me up and I couldn't aim my camera.
3. To clog or became entangled in something: The seaweed fouled up the propeller blades. The dangling cables fouled the machinery up, thereby causing the breakdown.
1. in. to blunder; to mess up. The quarterback fouled up in the first quarter, and that lost us the game.
2. n. a blunder; an error. (Usually foul-up.) That was a fine foul-up! Is that your specialty?
mod. messed up; ruined; tangled up. You sure are fouled up, you know.