Lewis & Short

ē-jūro (mostly post-Aug., Cic. Fam., v. infra, and ējĕro, like pejero, class., Scip. ap. Cic. de Or. 2, 70, 285 twice; Cic. Phil. 12, 7, 18; id. Verr. 2, 3, 60, § 137; Tert. Spect. 24; id. Idol. 18), āvi, ātum, 1, v. a., to refuse or reject by oath, to abjure, a t. t. of jurid., polit., and mercant. lang.

  1. I. In jurid. lang.: forum or judicem iniquum sibi, to reject, refuse on oath a court or a judge, as unjust, Scip. l. l.; Cic. Verr. l. l.; id. Phil. 12, 7, 18 Manut. and Wernsd.
  2. II. In polit. law lang.: magistratum, imperium, etc., to lay down, resign, abdicate an office, at the same time swearing to have administered it according to law: jurando abdicare, Tac. H. 3, 37; 68; 4, 39; id. A. 12, 4; Plin. Ep. 1, 23, 3; and absol., Tac. A. 13, 14.
      1. 2. Transf. beyond the polit. sphere (like abdicare), to abandon, forswear, disown any thing: militiam, to swear one’s self unfit for service, cf. III. infra; Plaut. Fragm. ap. Paul. ex Fest. p. 77, 17 Müll.: patriam, Tac. H. 4, 28; cf.: patriae nomen, Just. 12, 4, 1; Asin. Pollio ap. Sen. Suas. 7: liberos, Sen. Cons. ad Marc. 19; cf. patrem (with aversari), id. Ben. 6, 4.
        Poet.: fidem domitoremque inimicum (leo), Stat. Achill. 2, 188.
  3. III. In mercant. lang.: bonam copiam (as the opp. of jurare bonam copiam), to declare on oath that one has not wherewithal to pay his debts, to swear that one is insolvent, Cic. Fam. 9, 16, 7 Manut.