(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.

close close-knit close-textured close-woven closed compact compacted compressed concentrated concrete condensed congested consolidated crammed crammed full crowded dense firm gluey hard heavy hermetic holeproof impassable impenetrable impervious jam-packed jammed massive nonporous nonpuncturable packed punctureproof sealed serried solid substantial thick thick-growing thickset unpassable unperforable unpierceable viscid viscose viscous