When something goes bad, it means that it has become unsatisfactory and no longer useful or effective. There are a variety of synonyms that can be used to describe something that has gone bad, including: spoiled, rotten, decayed, putrid, rancid, stale, off, ruined, contaminated, and corrupted. Each of these words carries its own connotations and can be used in specific contexts. For example, spoiled food is typically associated with a foul smell or taste, while contaminated water may contain harmful bacteria. Whether describing food, relationships, or anything else that can go bad, there are numerous synonyms available to accurately capture the state of decay and decline.