in-nāvigābilis e, adj.,
not navigable: Tiberis, L.
in-nāvĭgābĭlis, e, adj., unnavigable : Tiberis, Liv. 5, 13, 1; Lact. 7, 16, 11. ...
A New Latin Dictionary by Charlton T. Lewis Ph.D. and Charles Short, LL. D.