impermeable
Americanadjective
-
not permeable; impassable.
-
Chemistry, Geology. (of porous substances, rocks, etc.) not permitting the passage of a fluid through the pores, interstices, etc.
adjective
Other Word Forms
Etymology
Origin of impermeable
From the Late Latin word impermeābilis, dating back to 1690–1700. See im- 2, permeable
Compare meaning
How does impermeable compare to similar and commonly confused words? Explore the most common comparisons:
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.
Vocabulary lists containing impermeable
"Simon's Saga," Vocabulary from Episode 32
Looking to grow your vocabulary? Check out this interactive, curated word list from our team of English language specialists at Vocabulary.com – one of over 17,000 lists we've built to help learners worldwide!
Challenge, List 12
Interested in learning more words like this one? Our team at Vocabulary.com has got you covered! You can review flashcards, quiz yourself, practice spelling, and more – and it's all completely free to use!
Girl, Interrupted
Want to remember this word for good? Start your learning journey today with our library of interactive, themed word lists built by the experts at Vocabulary.com – we'll help you make the most of your study time!
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.
Rain watered crops, and soaked in to recharge the groundwater that hydrated the city — something that can’t happen now, when something like 40% of the city is covered over, impermeable to rain.
From Los Angeles Times ● Sep. 17, 2026
“This was going to be impermeable and protected from attacks.”
From The Wall Street Journal ● Sep. 10, 2026
The ancient, ultra-hard material before them was, to most things, completely impermeable.
From BBC ● Aug. 18, 2026
Their technology involves pumping through fissures in the ground and squirting the carbon-rich material thousands of feet down, beneath a rock layer that should be impermeable for centuries.
From Salon ● Jul. 18, 2024
Those that come close suddenly change direction before hitting her glove, bouncing off as though she is surrounded by something invisible and impermeable.
From "The Night Circus" by Erin Morgenstern
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
