FOUL UP

{v.}, {informal} 1. To make dirty. * /The birds fouled up his newly washed car./ 2. To tangle up. * /He tried to throw a lasso but he got the rope all fouled up./ 3. To ruin or spoil by stupid mistakes; botch. * /He fouled the whole play up by forgetting his part./ 4. To make a mistake; to blunder. * /Blue suit and brown socks! He had fouled up again./ 5. To go wrong. * /Why do some people foul up and become criminals?/