Lewis & Short

pĕtītōrĭus, a, um, adj. [petitor].

  1. I. In gen., of or belonging to solicitation (post-class.): artes petitorias exercere, Mamert. Grat. Act. ad Jul. 16, 2.
  2. II. In partic., of or belonging to the prosecution of a judicial claim, petitory (post-class.): judicium, Dig. 6, 1, 36: formula, Gai. Inst. 4, 91 sq.
    Hence, subst.: pĕtītōrĭum, ii, n., the complaint or declaration in a private action, Cod. Th. 10, 10, 29, § 1.