Lewis & Short

regnum, i, n. [rex],

  1. I. kingly government, royal authority, kingship, royalty (cf.: imperium, principatus): cum penes unum est omnium summa rerum, regem illum unum vocamus et regnum ejus rei publicae statum, Cic. Rep. 1, 26, 42: regique Thebano Creonti regnum stabilivit suum, Plaut. Am. 1, 1, 39: regno regem spoliare, Cic. Rep. 1, 42, 65: ob labefactandi regni timorem, id. ib. 2, 2: regni initium, id. ib. 2, 15, 28: neque potest ejusmodi res publica non regnum et esse et vocari, royalty, id. ib. 2, 23: regnum obtinere, Caes. B. G. 5, 54; cf.: regnum in suā civitate occupare, id. ib. 1, 3: regnum reciperare, Auct. B. Alex. 36; Caes. B. G. 4, 12; 5, 20; 5, 25: dum stabat regno incolumis regumque vigebat Consiliis, Verg. A. 2, 88: Tulli ignobile regnum, Hor. S. 1, 6, 9; id. C. 1, 12, 34: Alexander periculoso regno securam ac tutam vitam anteponens, Just. 39, 4, 3.
    1. B. In gen., dominion, sovereignty, rule, authority.
      1. 1. In a good sense: possidere regna, Ter. Ad. 2, 1, 21: quod imperium, qui magistratus, quod regnum potest esse praestantius, quam, etc., Cic. Rep. 1, 17, 28: omne regnum vel imperium bellis quaeritur et victoriis propagatur, id. ib. 3, 12, 20: sibi a Caesare regnum civitatis deferri, Caes. B. G. 5, 6: ego te in meum regnum accepi, Sall. J. 10, 1: adoptione in regnum pervenire, id. ib. 11, 6: nationes, quae in eorum (i. e. Populi Romani) regno ac dicione sunt, Cic. Verr. 2, 4, 27, § 60: nobile regnum, Ov. H. 17, 133: regnum sine vi tenere, id. M. 11, 270: regnum alicui permittere, Hor. S. 1, 3, 123: bonae Sub regno Cinarae, id. C. 4, 1, 4: nec regna vini sortiere talis, the presiding over a drinking-bout, Gr. ἀρχιποσία, id. ib. 1, 4, 18 (cf.: arbiter bibendi, id. ib. 2, 7, 25; v. also rex).
      2. 2. In a bad sense, despotism, tyranny (to a Roman of the time of the Republic, any sovereignty of a single individual): hic ait se ille, judices, regnum meum ferre non posse. Quod tandem, Torquate, regnum? Consulatus, credo, mei … quo in magistratu non institutum est a me regnum, sed repressum, Cic. Sull. 7, 21; cf. Quint. 3, 8, 47: hoc vero regnum est, et ferri nullo pacto potest, Cic. Att. 2, 12, 1: Ti. Gracchus regnum occupare conatus est, id. Lael. 12, 41; so, occupare, id. Sull. 9, 27; id. Phil. 5, 6, 17: regnum appetere, id. Sen. 16, 56; id. Phil. 2, 44, 114; id. Mil. 27, 72 (for which affectare is cited, Quint. 5, 11, 12; v. Spald. N. cr. ad loc.): regnum judiciorum, Cic. Verr. 2, 1, 12, § 35; cf. forense, id. Fam. 9, 18, 1: quod tribuni militum in plebe Romanā regnum exercerent, Liv. 5, 2: damnatus crimine regni, Ov. F. 6, 189: dum regnum te, Roma, facit, i. e. gives thee a sovereign, Luc. 4, 692.
    2. C. Trop., rule, authority, power, influence: abuteris ad omnia atomorum regno et licentiā, Cic. N. D. 1, 23, 65: regnum voluptatis, id. Sen. 12, 41: sub regno tibi esse placet omnes animi partes et eas regi consilio? id. Rep. 1, 38, 60; Ov. M. 14, 20; Prop. 4 (5), 7, 50.
  2. II. Meton. (abstr. pro concreto), a kingdom: grates tibi ago, summe sol, quod conspicio in meo regno et his tectis P. Cornelium Scipionem, Cic. Rep. 6, 9, 9: ad fines regni sui, Caes. B. G. 5, 26; 5, 38: (flumen Mulucha) Jugurthae Bocchique regnum disjungebat, Sall. J. 92, 5: se patrio regno pulsos esse, Liv. 1, 40: (Aufidus) Qui regna Dauni praefluit Appuli, Hor. C. 4, 14, 26 al.: barbara regna, id. Ep. 2, 1, 253: regnum caelorum, Hier. adv. Jovin. 2, § 28; cf. Vulg. Matt. 13, 11 et saep.
    Poet., of bees: cerea regna refingunt, Verg. G. 4, 202.
    1. B. Transf.
      1. 1. Any place which one possesses, a territory, estate, possession: id, nisi hic in tuo regno essemus, non tulissem, i. e. on your own territories, on your own estate, Cic. de Or. 1, 10, 41; cf. id. Att. 14, 16, 1: post aliquot mea regna videns, mirabor aristas? fields, Verg. E. 1, 70; cf. id. G. 1, 124; 3, 476: regna videt pauper Nasamon errantia vento, his cottages, Luc. 9, 458 al.: haec regna, these realms, i. e. of the dead, Verg. A. 6, 417.
      2. 2. Regna = reges, Stat. Th. 12, 380.