petitioner

noun

1. a solemn, earnest supplication or request to a superior or deity or to a person or group in authority; prayer or entreaty
2. a formal writing or document embodying such a request, addressed to a specific person or group and often signed by a number of petitioners
3. something that is asked or entreated: to grant a petition
4. Law a written formal request or plea in which specific court action is asked for: a petition for rehearing

Origin: OFr < L petitio (gen. petitionis) < petere, to seek, rush at, fall: see feather

transitive verb

1. to address a petition to; ask formally or earnestly
2. to ask for; solicit

intransitive verb