A petitioner is someone who makes a formal request to an authority or court. The term can be used in various contexts, such as a SUER (4 letters), who is someone who initiates a lawsuit; an APPLICANT (9 letters), who is someone who applies for something; a SUITOR (6 letters), who is someone who courts another person; a SEEKER (6 letters), who is someone who looks for something; a CLAIMANT (8 letters), who is someone who asserts a right to something; a supplicant (10 letters), who is someone who humbly requests something; a SUPPLIANT (9 letters), who is someone who entreats for something; a bidder (6 letters), who is someone who offers a price for something; an APPELLANT (9 letters), who is someone who appeals a decision; and a CANVASSER (9 letters), who is someone who solicits votes or orders.