from The American Heritage® Dictionary of the English Language, 4th Edition

  • adj. Impossible to permeate: an impermeable membrane; an impermeable border.

from Wiktionary, Creative Commons Attribution/Share-Alike License

  • adj. impossible to permeate
  • adj. not allowing passage, especially of liquids; waterproof

from the GNU version of the Collaborative International Dictionary of English

  • adj. Not permeable; not permitting passage, as of a fluid. through its substance; impervious; impenetrable.

from The Century Dictionary and Cyclopedia

  • Not permeable; not permitting the passage of a fluid (especially water) through its substance.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

  • adj. preventing especially liquids to pass or diffuse through


from Wiktionary, Creative Commons Attribution/Share-Alike License

From Latin impermeābilis, from im- + permeābilis ("permeable").


  • On the wall hung a simple chart of a rock formation with layers labelled impermeable, source, permeable and reservoir; a list saying things like spudded Oct. '71, plugged and abandoned Jan.' 72; and three brightly coloured maps of the North Sea, each of them showing a different aspect of the oil drilling operations going on there.

    Slay Ride

  • The old operation of "perineal section" for so-called impermeable stricture is very different, being difficult, dangerous, and uncertain in its results.

    A Manual of the Operations of Surgery For the Use of Senior Students, House Surgeons, and Junior Practitioners

  • Many geothermal reservoirs have heat, but the rock is impermeable, which is the problem at the Raft River well known as RRG-9.

    Reliable Plant Magazine

  • His dream, as he told the American people, was to create an "impermeable" anti-missile shield over the United States -- "like a roof protects a family from rain" -- that would end the possibility of nuclear attack from the Soviet Union and so create peace in our time (or, if you were of a more cynical turn of mind, the possibility of a freebie nuclear assault on the Soviets).

    Tom Engelhardt: Why Military Dreams Fail -- and Why It Doesn't Matter

  • In effect, social scientists treat the life sciences as enclosed within a kind of impermeable wall.

    Easter Lemming Liberal News

  • Igneous rock types like basalt have very small mineral grains and are thus deigned "impermeable" although the term means "barely" rather than "absolutely not" permeable, and are formed by lava cooling at the earth's surface; others, like granite, have larger pores and are formed by lava flows which cool much more slowly underground.

    Archive 2006-09-01

  • Vittorio took them there in the hooded gondola, himself radiant in a new "impermeable" hat and coat, which gave him the appearance of a gigantic wet seal, swaying genially on its supple tail.

    A Venetian June

  • When word of the dispute reached AGO director and CEO Matthew Teitelbaum that November, he said he was confident the newly renovated Gallery would be "impermeable" and ready for the challenging weather of downtown Toronto.

    The Globe and Mail - Home RSS feed

  • included a magnified view showing how difficult it is for water molecules to navigate their way through the mineral grains of an "impermeable" rock; or, most importantly, added an unconfined aquifer above the impermeable layer the most common real scenario anyway to show where the rain actually goes, and to highlight the distinction between a confined source and an unconfined one.

    The Confusing Diagram on FIJI Water Bottles: Or, Why Good Designers Are Worth Their Weight In Gold

  • One enormously influential aspect of the Phoenician system of writing was that it allowed the average person to learn its phonetic symbols and sounds fairly easily, and so to attain literacy at a time when reading and writing—long shrouded in mystery—were effectively monopolized by members of a privileged and impermeable caste.

    The English Is Coming!


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