Im·per·me·a·ble a.  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.
  ◄ ►
  impermeableness
       n : the property of something that cannot be pervaded by a
           liquid [syn: impermeability] [ant: permeability]