Lewis & Short

1. concordĭa, ae, f. [concors], an agreeing together, union, harmony, concord (opp. discordia, Sall. J. 10, 6; Sen. Ep. 94, 46; opp. bellum, Lucr. 1, 457; opp. repugnantia, Plin. 29, 4, 17, § 61; freq. and class. in prose and poetry).

  1. I. Of persons: redigere aliquem in antiquam concordiam alicujus, Plaut. Am. 1, 2, 13; cf.: redire in concordiam, id. ib. 3, 3, 7: conjunctio atque concordia, Cic. Verr. 2, 3, 9, § 23: conspiratio atque concordia omnium ordinum ad defendendam libertatem, Lentulus ap. Cic. Fam. 12, 15, 3: equites concordiā conjunctissimi, Cic. Clu. 55, 152: de equestri concordiā, de consensione Italiae, id. Att. 1, 14, 4; Liv. 4, 43, 11: quorum perpetuam vitae concordiam mors quoque miscuit, id. 40, 8, 15: de reconciliandā concordiā agere, id. 41, 25, 2: concordiam confirmare cum aliquo, Cic. Phil. 13, 1, 2: ut (dissensiones) non reconciliatione concordiae, sed internicione civium dijudicatae sint, id. Cat. 3, 10, 25: agi deinde de concordiā coeptum, Liv. 2, 33, 1: aliquos in pristinam concordiam reducere, Balb. ap. Cic. Att. 8, 15, A, 1: ad concordiam hortare, Quint. 6, 1, 50; cf.: concordiam suadere, Suet. Oth. 8: ordinum concordiam disjunxit, Cic. Att. 1, 18, 3: si Caesar ejus aspernaretur concordiam, his friendship, alliance, Vell. 2, 65, 1: Temporis angusti mansit concordia discors, i. e. feigned friendship, Luc. 1, 98; cf. II. infra.
    1. B. Poet., meton. (abstr. pro concr.), an intimate friend: et cum Pirithoo, felix concordia, Theseus, Ov. M. 8, 303.
  2. II. Of inanim. and abstr. things: vocum, Col. 12, 2, 4 (acc. to Cic. Oecon.); cf.: concordia sociata nervorum, Quint. 5, 10, 124: concordia quam magnes cum ferro habet, Plin. 34, 14, 42, § 147: illa dissimilium concordia, quam vocant ἁρμονίαν, Quint. 1, 10, 12; cf. thus discors (rerum), νεῖκος καὶ φιλία, Ov. M. 1, 433; Hor. Ep. 1, 12, 19: poëtae discordiā concordiā mundum constare dixerunt, Lact. 2, 9, 17: rerum agendarum ordo et, ut ita dicam, concordia, Cic. Fin. 3, 6, 21: quia (temperantia) pacem animis adferat et eos quasi concordiā quādam placet ac leniat, by a certain equanimity, id. ib. 1, 14, 47: Sirenum, the harmonious singing, Petr. 127 al.