When it comes to describing something that is not true, there are plenty of different synonyms you could use. For example, you might say that something is false, incorrect, inaccurate, or untrue. Other options might include phrases like "not factual," "without basis," "falsehood," or "misleading." Depending on the context, you might use more specific terms like "fraudulent," "deceptive," or "fabricated." Ultimately, the synonym you choose will depend on the specific situation you're talking about and the level of emphasis you want to place on the fact that something is not true.