impermeable       
adjective uk/ɪmˈpɜː.mi.ə.bəl/ us/ɪmˈpɝː.mi.ə.bəl/
 不可渗透的;不透气的
not allowing liquid or gas to go through
  an impermeable membrane 防渗透薄膜 
 Synonyms: impenetrableimpervious (SUBSTANCE) 
Compare: waterproof adjectivewatertight (NO WATER)weatherproof adjective
Opposite: permeable