D defs.my
Entry 1 sense Webster, 1913

Impermeable

· Im·per·me·a·ble · IPA /ɪmˈpɝmɪəbəl/
01 a. Not permeable; not permitting passage, as of a fluid. through its substance; impervious; impenetrable; as, India rubber is impermeable to w…
  1. 1.
    Not permeable; not permitting passage, as of a fluid. through its substance; impervious; impenetrable; as, India rubber is impermeable to water and to air.