Balls-up is a colloquial expression that is commonly used to describe a mess or a mistake. It is a slang term that originated in the UK and is frequently used in informal contexts. However, there are several other words that can be used as synonyms for balls-up such as fiasco, blunder, mishap, snafu, debacle, and disaster. These words convey the same meaning as balls-up and are commonly used in formal writing and official communication. Furthermore, these synonyms help to add variety to one's writing and speech, resulting in a more engaging and informative conversation or written work.