Adjective
Incapable of being passed; not admitting a passage; as, an impassable road, mountain, or gulf.
Source: Webster's dictionaryAfter a few days' travel they soon discovered that steep canyons, waterfalls and impassable rapids made travel by river impossible. Source: Internet
Both rapids were considered virtually impassable. Source: Internet
During the rainy season from July to October, some roads are impassable. Source: Internet
Flooding during the April to December rainy season occasionally makes city streets impassable and washes out some roads in the interior of the country. Source: Internet
Hardin (1994), p. 245. Spring rains ruined the ammunition and rendered the roads almost impassable, with troops sinking to their knees in mud. Source: Internet
He crossed without opposition over both the Apennines (during which he lost his right eye citation because of conjunctivitis ) and the seemingly impassable Arno, but he lost a large part of his force in the marshy lowlands of the Arno. Source: Internet