The term foul-up typically means a mistake or error, but it also has opposite words that describe the opposite of a mistake. One of the antonyms for foul-up is success, which is defined as a positive outcome of an endeavor. Another antonym is accuracy, which means the degree to which something is correct or free from errors. Precision can also be considered as an antonym for foul-up, as it refers to the exactness or accuracy of something. Finally, the term perfection is another antonym for foul-up, which signifies the state of fulfilling every requirement or standard of excellence.