im·​per·​me·​able | \ (ˌ)im-ˈpər-mē-ə-bəl \

Definition of impermeable

: not permitting passage (as of a fluid) through its substance broadly : impervious

Keep scrolling for more

Other Words from impermeable

impermeability \ (ˌ)im-​ˌpər-​mē-​ə-​ˈbi-​lə-​tē \ noun

Examples of impermeable in a Sentence

an impermeable layer of rock a fabric impermeable to moisture

Recent Examples on the Web

Waste will be sealed in the copper coffins, placed into the storage shafts, and surrounded by a thick layer of bentonite, a natural clay almost impermeable to water. Tim Heffernan, Popular Mechanics, "Finland's Crazy Plan to Make Nuclear Waste Disappear," 10 May 2012 For storms like Harvey, changes in land use that come with urbanization, such as replacing permeable surfaces like grass with impermeable surfaces like concrete, can cause big changes in water runoff. Kara Dapena, WSJ, "The Rising Costs of Hurricanes," 29 Sep. 2018 The thermal spring water and glycerin, a humectant that attracts water, in the formula work to instantly flood your skin with hydration, while the oil creates an impermeable barrier to lock it in. Rachel Jacoby Zoldan, Glamour, "The No-Frills Face Cream That Tackles the Toughest Dry Spots," 27 Aug. 2018 Among those, Buczak said, are construction of a breakwater containing an impermeable structure that would do a better job of protecting the path by keeping the water out. Blair Kamin,, "Northerly Island walkway still mangled and off-limits: Here's the story behind this engineering flop," 27 Apr. 2018 Outside of these areas, the membrane formed as usual, creating an impermeable barrier. John Timmer, Ars Technica, "Alan Turing’s chemistry hypothesis turned into a desalination filter," 5 May 2018 Below that is a layer of impermeable clay, followed by a separate layer of saltwater. Alan Gomez, USA TODAY, "Salmon from sunny South Florida? Norwegian firm builds Florida farm for cold-water fish," 11 Apr. 2018 Construction—laying down impermeable surfaces like concrete where there was once dirt or wetland—makes floods worse. Adam Rogers, WIRED, "Hurricane Season 2018 Has a Lot to Learn From Last Year," 1 June 2018 Furthermore, Facebook doesn’t really make people connect with one another across once-impermeable borders. Alex Shephard, The New Republic, "Why Facebook Is Desperate for Conservative Allies," 4 May 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'impermeable.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

See More

First Known Use of impermeable

1697, in the meaning defined above

History and Etymology for impermeable

Late Latin impermeabilis, from Latin in- + Late Latin permeabilis permeable

Keep scrolling for more

Learn More about impermeable

Share impermeable

Statistics for impermeable

Look-up Popularity

Time Traveler for impermeable

The first known use of impermeable was in 1697

See more words from the same year

Keep scrolling for more

More Definitions for impermeable



English Language Learners Definition of impermeable

technical : not allowing something (such as a liquid) to pass through


im·​per·​me·​able | \ (ˈ)im-ˈpər-mē-ə-bəl \

Medical Definition of impermeable

: not permitting passage (as of a fluid) through its substance the plasma membrane of a red blood cell is relatively impermeable to sodium and calcium ions

Other Words from impermeable

impermeability \ (ˌ)im-​ˌpər-​mē-​ə-​ˈbil-​ət-​ē \ noun, plural -ties

Keep scrolling for more

Comments on impermeable

What made you want to look up impermeable? Please tell us where you read or heard it (including the quote, if possible).


marked by fawning attentiveness

Get Word of the Day daily email!

Test Your Vocabulary

What did you just call me?! A Quiz

  • rows-of-various-emoji
  • If a member of the audience describes your speech as bombastic, does that person mean it is:
How Strong Is Your Vocabulary?

Test your vocabulary with our 10-question quiz!

Add Diction

Test Your Knowledge - and learn some interesting things along the way.


Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!