I / invĭus
adjective

invĭus

fem. invia · neut. invium
without a road; impassable
without a road, impassable (syn.: inaccessus, devius; not in Cic. or Cæs.).
Neutr; impassable places
Lit.: lustra, Verg. A. 4, 151: longa via, id. ib. 3, 383: saltus, Liv. 9, 14: per invias atque ignotas rupes iter, id. 38, 2 fin.: saxa, Verg. A. 1, 537: maria Teucris, Verg. A. 9, 130: rupibus regio, Plin. 12, 14, 30, § 52: virtuti nulla est via, Ov. M. 14, 113.— Neutr.: nil virtuti invium, Tac. Agr. 27.— With inf.: Acheron invius renavigari, Sen. Herc. Fur. 715. — Subst.: invĭa, ōrum, n. plur., impassable places: per invia pleraque et errores, Liv. 21, 35: per vias inviaque, id. 23, 17: per vias, per invia, id. 38, 23: dumosa, Sil. 4, 305.—
inaccessible; impenetrable by extension
Transf., inaccessible, impenetrable: regna, impenetrable, Verg. A. 6, 514: templa, Ov. M. 11, 414: tot bellis invia tecta, Sil. 14, 639: Sarmaticis lorica sagittis, Mart. 7, 2.