Crud up is a colloquial expression used to describe something that has gone wrong or has been ruined. There are many synonym replacements for this expression that can be used to express similar sentiments. Some synonyms include botch, flub, mess up, bungle, blunder, fumble, spoil, wreck, and ruin. All of these words suggest a mistake or error that has occurred, resulting in a negative outcome. Whether it be a failed project or a ruined meal, these synonyms can be used to describe the situation in a way that is relatable and understandable to others.