What is a prepistiton?

It seems there might be a typo in your question, as "prepistiton" does not appear to be a recognized term. If you meant "preposition," it refers to a Word that links nouns, pronouns, or phrases to other Words within a sentence, indicating relationships of time, place, direction, or manner (e.g., in, on, at, during). If you meant something else, please clarify!