Source : Webster's Revised Unabridged Dictionary (1913)

Petit \Pet"it\, a. [F. See {Petty}.]
   Small; little; insignificant; mean; -- Same as {Petty}.
   [Obs., except in legal language.]

         By what small, petit hints does the mind catch hold of
         and recover a vanishing notion.          --South.

   {Petit constable}, an inferior civil officer, subordinate to
      the high constable.

   {Petit jury}, a jury of twelve men, impaneled to try causes
      at the bar of a court; -- so called in distinction from
      the grand jury.

   {Petit larceny}, the stealing of goods of, or under, a
      certain specified small value; -- opposed to grand
      larceny. The distinction is abolished in England.

   {Petit ma[^i]tre}. [F., lit., little master.] A fop; a
      coxcomb; a ladies' man. --Goldsmith.

   {Petit serjeanty} (Eng. Law), the tenure of lands of the
      crown, by the service of rendering annually some implement
      of war, as a bow, an arrow, a sword, a flag, etc.

   {Petit treason}, formerly, in England, the crime of killing a
      person to whom the offender owed duty or subjection, as
      one's husband, master, mistress, etc. The crime is now not
      distinguished from murder.

Source : WordNet®

petit jury
     n : a jury of 12 to determine the facts and decide the issue in
         civil or criminal proceedings [syn: {petty jury}]