a. [ Pref. im- not + permeable: cf. F. imperméable, L. impermeabilis. ] Not permeable; not permitting passage, as of a fluid. through its substance; impervious; impenetrable;
a. [ L. permeabilis: cf. F. perméable. See Permeate. ] Capable of being permeated, or passed through; yielding passage; passable; penetrable; -- used especially of substances which allow the passage of fluids;