Lewis & Short

prōlŏquĭum, ĭi, n. [proloquor].

  1. * I. An introduction, preamble, Paul. ex Fest. p. 226 Müll.; v. prologium.
  2. II. An assertion, proposition, axiom (class. Lat. pronunciatum), the Gr. ἀξίωμα, Varr. ap. Gell. 16, 8, 1; cf. App. Dogm. Plat. 3, p. 29, 15: disjunctivum, Gell. 5, 11, 9.
  3. III. A judicial sentence: sub uno proloquio cunctos jubet occidi, Amm. 29, 1, 38; 28, 1, 11.