adversary proceeding: A lawsuit arising in or related to a bankruptcy case that is commenced by filing a complaint with the court. A nonexclusive list of adversary proceedings is set forth in Fed. R. Bankr. P. 7001.
bankruptcy petition: The document filed by the debtor (in a voluntary case) or by creditors (in an involuntary case) by which opens the bankruptcy case. (There are official forms for bankruptcy petitions.)