Lewis & Short

in-victus, a, um, adj. [2. in], unconquered, unsubdued, not vanquished; hence unconquerable, invincible; constr. with ab, in and abl. or acc., ad, contra, adversum, the simple abl., with gen. and inf. (class.).

        1. (α) With ab: invictum se a labore praestare, Cic. Off. 1, 20, 68: invictus a civibus hostibusque animus, Liv. 22, 26: Fabius prius ab illis invictum animum praestat, id. 22, 15, 1: vos, hoc est populus Romanus, invicti ab hostibus, Sall. J. 31, 20: a cupiditatibus animus, Liv. 39, 40; 22, 26 fin.
        2. (β) With in and abl.: spartum in aquis, marique invictum, Plin. 19, 2, 8, § 29.
        3. (γ) With in and acc.: in hostem et in mortem invictus animus, Just. 12, 15.
        4. (δ) With ad: invictum ad vulnera corpus, Ov. M. 12, 167.
          (ε) With contra: crocodilus contra omnes ictus cute invicta, Plin. 8, 25, 37, § 89.
          (ζ) With adversus or adversum: adversum divitias invictum animum gerebat, Sall. J. 43, 5; so Sen. Helv. 5, 5; Tac. A. 15, 21.
          (η) With simple abl.: armis invictus, Cic. Agr. 2, 35, 95: invicti viribus, Verg. A. 6, 394: certamine, Ov. M. 7, 792: cursu, id. ib. 8, 311: caestibus, id. ib. 5, 107: robore, Luc. 4, 608: invictaque bello dextera, Verg. A. 6, 878: dentes ignibus, Plin. 7, 6, 15, § 70.
          (θ) With the gen. and inf. (poet.): Cantaber hiemisque aestusque famisque Invictus, palmamque ex omni ferre labore, Sil. 3, 326.
          (ι) With dat. cunctis, Luc. 4, 608; cf. Tac. Agr. 18.
          (κ) Absol.: Germani, Caes. B. G. 1, 36: ambae invictae gentes, Verg. A. 12, 191: satis vixi, invictus enim morior, Epam. ap. Nep. Epam. 9, 4: Hannibal, Nep. Hann. 6, 1: nomen invicti imperatoris, Cic. Verr. 2, 4, 38, § 82: dux, Ov. Tr. 4, 2, 44; Luc. 5, 324; 10, 346: res publica, Cic. Par. 4, 29: imperium, Liv. Epit. 3: Palladis manus, Ov. Am. 3, 3, 28: virtus, id. P. 3, 4, 111: invictae opinionis exercitus, reputed invincible, Just. 33, 1, 3: adamas, impenetrable, Ov. P. 4, 12, 32.
          Comp.: invictior ratio, irrefutable, Aug. de Immort. Anim. 8.
          Sup.: omnes sciunt te unum in terra vivere virtute et forma et factis invictissumum, not to be surpassed, Plaut. Mil. 1, 1, 57; Symm. Ep. 10, 78.
          Hence, invictē, adv., invincibly, irrefutably (eccl. Lat.): invictissime, Aug. Ep. 28.