"Hath notion" is an archaic term that is no longer commonly used in modern English. Instead, there are many synonyms that are more commonly used to express the same idea. For example, "hath notion" could be replaced with "has an idea," "has a belief," "holds a perspective," or "entertains a notion." In more casual language, one might use "thinks" or "feels." There are many different ways to convey the idea expressed by "hath notion," and the choice of synonym depends on the context and tone of the piece of writing or conversation.