A solemn supplication or request to a superior authority; an entreaty. A formal written document requesting a right or benefit from a person or group in authority. Law A formal written application requesting a court for a specific judicial action: a petition for appeal. Law The judicial action asked for in any such request. Something requested or entreated. To address a petition to. To ask for by petition; request formally. To make a request, especially formally: petitioned for retrial.