Lewis & Short

impĕrātōrĭus (inp-), a, um, adj. [imperator].

  1. I. Of or belonging to a general (class.): quod ipse honos laborem leviorem faceret imperatorium, Cic. Tusc. 2, 26, 62: jus, id. Verr. 2, 1, 21, § 57; cf. partes (shortly before: imperatoris partes), Caes. B. C. 3, 51, 5: nomen, Cic. Fam. 11, 4, 1; Tac. A. 1, 3: consilium, Cic. N. D. 3, 6, 15: laus, id. Ac. 2, 1, 2: virtus, Quint. 7, 10, 13; 8, 2, 11: ars, id. 2, 17, 34: manubiae, Cic. de Or. 3, 3, 10: pulvis sudorque (opp. campestris meditatio), Plin. Pan. 13, 1: navis, an admiral’s ship, Plin. 19, 1, 5, § 22.
    * Adv.: impĕrātōrĭē, like a general: dum se ad id bellum imperatorie instruit, Treb. Claud. 6.
  2. II. (Acc. to imperator, II. B. 3.) Imperial: genesis, Suet. Dom. 10: munera, id. Vesp. 24: onera, id. Calig. 42.