Preventing especially liquids to pass or diffuse through.

Roget 261: closed etc. v.; shut, operculated^†; unopened.    unpierced^†, imporous^†, caecal [Med.]; closable; imperforate, impervious, impermeable; impenetrable; impassable, unpassable^†; invious^†; pathless, wayless^†; untrodden, untrod.    unventilated; air tight, water tight; hermetically sealed; tight, snug.    ... show more

Roget 321: dense, solid; solidified etc. v.; caseous; pukka^†; coherent, cohesive etc. 46; compact, close, serried, thickset; substantial, massive, lumpish^†; impenetrable, impermeable, nonporous, imporous^†; incompressible; constipated; concrete etc. (hard) 323; knotted, knotty; gnarled; crystalline, crystallizable; thick, grumous^†, stuffy.    undissolved, unmelted^†, unliquefied^†, unthawed^†.    indivisible, indiscerptible^†, infrangible^†, indissolvable^†, indissoluble, insoluble, infusible.    ... show more

Dutch: ondoordringbaar