Meaning of impermeable

im•per•me•a•ble

Pronunciation: (im-pûr'mē-u-bul), [key]
— adj.
  1. not permeable; impassable.
  2. (of porous substances, rocks, etc.) not permitting the passage of a fluid through the pores, interstices, etc.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.
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