Balls up is a slang term frequently used to describe a situation that is messed up or gone wrong. There are various synonyms that can be used for this phrase; some of the popular substitutes include: botch, blunder, fumble, mess up, screw up, flub, and muff. These words all refer to making an error or mistake, often resulting in negative consequences. While they may be used in different contexts, they all ultimately indicate an action that was poorly executed or planned. In professional settings, it is important to use more appropriate language, but among friends or in casual conversations, these slang words can be used to express frustration or disappointment.