Source : Webster's Revised Unabridged Dictionary (1913)

Petition \Pe*ti"tion\, v. t. [imp. & p. p. {Petitioned}; p. pr.
   & vb. n. {Petitioning}.]
   To make a prayer or request to; to ask from; to solicit; to
   entreat; especially, to make a formal written supplication,
   or application to, as to any branch of the government; as, to
   petition the court; to petition the governor.

         You have . . . petitioned all the gods for my
         prosperity.                              --Shak.

Petition \Pe*ti"tion\, n. [F. p['e]tition, L. petitio, fr.
   petere, petitum, to beg, ask, seek; perh. akin to E. feather,
   or find.]
   1. A prayer; a supplication; an imploration; an entreaty;
      especially, a request of a solemn or formal kind; a prayer
      to the Supreme Being, or to a person of superior power,
      rank, or authority; also, a single clause in such a
      prayer.

            A house of prayer and petition for thy people. --1
                                                  Macc. vii. 37.

            This last petition heard of all her prayer.
                                                  --Dryden.

   2. A formal written request addressed to an official person,
      or to an organized body, having power to grant it;
      specifically (Law), a supplication to government, in
      either of its branches, for the granting of a particular
      grace or right; -- in distinction from a memorial, which
      calls certain facts to mind; also, the written document.

   {Petition of right} (Law), a petition to obtain possession or
      restitution of property, either real or personal, from the
      Crown, which suggests such a title as controverts the
      title of the Crown, grounded on facts disclosed in the
      petition itself. --Mozley & W.

   {The Petition of Right} (Eng. Hist.), the parliamentary
      declaration of the rights of the people, assented to by
      Charles I.

Petition \Pe*ti"tion\, v. i.
   To make a petition or solicitation.

Source : WordNet®

petition
     n 1: a formal message requesting something that is submitted to
          an authority [syn: {request}, {postulation}]
     2: reverent petition to a deity [syn: {prayer}, {orison}]
     v : write a petition for something to somebody; request formally
         and in writing