Lewis & Short

obsĭdĭo, ōnis, f. [obsideo].

  1. I. Lit.
    1. A. In gen., a siege, investment, blockade of a place (class.): obsidionem potias dicendum esse, quam obsidium, adjuvat nos testimonio suo Ennius in Telamone, Paul. ex Fest. p. 198 Müll.; v. Müll. ad loc.; and cf.: cui tu obsidionem paras, Enn. ib. (Trag. v. 365 Vahl.); and: obsidionem obducere, id. ib. (Trag. v. 11 ib.): partim vi, partim obsidione urbes capere, Cic. Mur. 9, 20: aliquem in obsidione habere, Caes. B. C. 3, 31: cum spes major Romanis in obsidione quam in oppugnatione esset, Liv. 5, 2: obsidione eximere, to free or relcase from, id. 38, 15: obsidione cingere, to besiege, blockade, Just. 22, 4, 1; Verg. A. 3, 52: obsidionem tolerare, to stand, Tac. H. 1, 33: obsidionem exsequi, to carry on, id. A. 15, 4: obsidionem omittere, to raise, id. ib. 15, 5: obsidionem solvere, to put an end to a siege, by either surrender or relief: tolerando paucos dies totam soluturos obsidionem, Liv. 26, 7, 8; cf. Amm. 20, 7, 3: solutā obsidione, raised, Liv. 36, 31, 7; Curt. 4, 4, 1: eam obsidionem sine certamine adveniens Cn. Scipio solvit, Liv. 24, 41, 11; 25, 22, 15; 38, 5, 6; Just. 4, 4, 5; Tac. A. 4, 24; id. H. 4, 34: liberare obsidionem, to raise the siege: non ad Romam obsidendam, sed ad Capuae liberandam obsidionem Hannibalem ire, Liv. 26, 8, 5; cf. obsidium fin.: longae dira obsidionis egestas, Juv. 15, 96.
    2. B. Transf., captivity (post-class.), Just. 2, 12, 6; 15, 1, 3; 39, 1, 1.
  2. II. Trop., pressing, imminent danger: obsidione rem publicam liberare, Cic. Rab. Perd. 10, 29: feneratores ex obsidione eximere, to free from the danger of losing their money, id. Fam. 5, 6, 3; Plin. Pan. 81, 2; cf. obsidium.