"Negatable" is a word used to describe something that can be cancelled or undone. However, there are various other synonyms that can be used in place of "negatable" depending on the context. Some of these synonyms include "reversible", "annullable", "revocable", "invoidable", "voidable", "rescindable", and "cancellable". Each of these words carries a slightly different connotation and may be more appropriate for different situations. For example, "reversible" may be better suited for talking about the actions that can be undone, while "voidable" may be more appropriate when discussing contracts or agreements that can be invalidated. Overall, having a wide range of synonyms can help to add nuance and depth to communication.