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Synonyms

impermeable

American  
[im-pur-mee-uh-buhl] / ɪmˈpɜr mi ə bəl /

adjective

  1. not permeable; impassable.

  2. Chemistry, Geology. (of porous substances, rocks, etc.) not permitting the passage of a fluid through the pores, interstices, etc.


impermeable British  
/ ɪmˈpɜːmɪəbəl /

adjective

  1. (of a substance) not allowing the passage of a fluid through interstices; not permeable

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

impermeable Scientific  
/ ĭm-pûrmē-ə-bəl /
  1. Relating to a material through which substances, such as liquids or gases, cannot pass. Some substances, such as some types of contact lenses, are permeable to gas but impermeable to liquid.


Other Word Forms

Etymology

Origin of impermeable

From the Late Latin word impermeābilis, dating back to 1690–1700. See im- 2, permeable

Compare meaning

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Explanation

If you have a waterproof raincoat, you could say that your coat is impermeable to the rain. Something that is impermeable does not allow water or liquid to pass through it. Made up of the prefix im-, meaning “not,” and the adjective permeable, meaning “allowing to pass through,” impermeable is used in much the same way as impervious or impenetrable. However, more so than these words, impermeable is especially associated with liquids and is often used in a scientific or technical context. Some gadgets, like waterproof watches and underwater cameras, are designed to be impermeable.

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Vocabulary lists containing impermeable

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

Impermeable strictures of the cervical esophagus are amenable to external esophagotomy, with plastic reformation of the esophagus.

From Bronchoscopy and Esophagoscopy A Manual of Peroral Endoscopy and Laryngeal Surgery by Jackson, Chevalier

Impermeable rugs and fleecy shawls, head-gear to defy the rudest northeasters, sea-chairs of ample dimensions, which we took care to place in as sheltered situations as we could find,—all these were a matter of course.

From Our Hundred Days in Europe by Holmes, Oliver Wendell

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