Im*per"vi*ous (?), a. [L. impervius; pref. im- not + per through + via way. See Voyage.]
Not pervious; not admitting of entrance or passage through; as, a substance impervious to water or air.
This gulf impassable, impervious.
The minds of these zealots were absolutely impervious.
Syn. -- Impassable; pathless; impenetrable; imperviable; impermeable.
-- Im*per"vi*ous*ly, adv. -- Im*per"vi*ous*ness, n.
© Webster 1913.