Idiom: Foul UpCheck definitions of...foulupMeaningsHow to pronounce "foul up":AU Your browser does not support the audio element. To make a mistake, to go wrong.To botch; to make a mess of.A-Z Proximitiesforked tongueFort Knoxforty minutes of hellforty winksforward-leaning foul up fountain of youthfour-eyesFour Horsemen of the Apocalypsefour score and seven years agofour sheets to the windSimilar Idiomscry foulfall foulfoul upin one foul swoopno harm, no foulSimilar Phrasesfoul ballfoul linefoul outfoul playfoul shotfoul-weather gearpersonal foultechnical foul