Lewis & Short

1. mīlīārīus or millĭārĭus, a, um, adj. [mille], containing or comprising a thousand.

  1. I. Adj.: decuriae, Varr. L. L. 9, § 87 Müll.: greges, id. R. R. 2, 10: clivus, of a thousand paces, id. ib. 3, 1: apri, weighing a thousand pounds, Sen. Ep. 110, 12: oleae, Plin. 17, 12, 19, § 93: ala, of a thousand men, Plin. Ep. 7, 31: COHORS, Inscr Grut. 482, 4: porticus, a thousand feet in length, Suet. Ner. 31: aevum, of a thousand years, Tert Anim 31.
  2. II. Subst.
    1. A. mīlĭārĭum (mill-), ii, n.
      1. 1. A mile-stone (which indicated a distance of a thousand paces, i. e. a Roman mile): cum plebes prope ripam Anienis ad tertium miliarium consedisset, Cic. Brut. 14, 54: intra primum urbis Romae miliarium, Gai. Inst. 4, 104: intra centesimum urbis Romae miliarium, within a hundred miles of Rome, id. ib. 1, 27.
        In partic.: miliarium or miliarium aureum, the mile-stone set up by Augustus in the forum, as the terminal point of all military roads: mille passus non a miliario Urbis, sed a continentibus aedificiis numerandi sunt, Dig. 50, 16, 154; Suet. Oth. 6; Plin. 3, 5, 9, § 66; Tac. H. 1, 27.
        Plur: miliaria lapidea, Aug. Serm. 351, 11.
          1. (β) Transf., a Roman mile, a mile, Suet. Ner. 31.
      2. 2. The number one thousand, a thousand, Varr. L. L. 9, § 82 Müll.: annorum, a space of a thousand years, Aug. Civ. Dei, 20, 7.
    2. B. mīlĭārĭi (mill-), ōrum, m., a Christian sect who believed in the doctrine of a millennial kingdom, the Millenarians, Chiliasts, Aug. Haeres. 8; id. Civ. Dei, 20, 7, 1; Hier. praef. libri 18 in Isa. 66, 33.