The term "not purpose" refers to something that is not intended or meant to happen. Synonyms for this phrase include accidental, unintentional, incidental, fortuitous, unforeseen, and unplanned. These words indicate that something happened without being planned, intended, or expected. For instance, an accidental injury is something that happened unintentionally, whereas a fortuitous event is one that occurs by chance or luck. When it comes to writing, using synonyms for "not purpose" can help to add variation and interest to your text. It's important to choose the right word depending on the context and the specific situation you are describing.