What is a petishion?

Answer 1

The word you are looking for is petition.

In the legal context, it is a written request asking someone for something.

Answer 2

It seems like there might be a spelling error in your question. If you meant "petition," it is a formal request for something, typically written and signed by multiple people in order to bring attention to a specific issue or cause. Petitions are often used to advocate for change or to express a collective opinion.