Impermeable
Pronunciation : Im*per"me*a*ble
Part of Speech : a.
Etymology : [Pref. im- not + permeable: cf. F. imperm?able, L. impermeabilis.]
Definition : Defn: Not permeable; not permitting passage, as of a fluid. through its substance; impervious; impenetrable; as, India rubber is impermeable to water and to air. -- Im*per"me*a*ble*ness, n. -- Im*per"me*a*bly, adv.
Source : Webster's Unabridged Dictionary, 1913