impermeable
adjective
im·per·me·able
(ˌ)im-ˈpər-mē-ə-bəl 
: not permitting passage (as of a fluid) through its substance
broadly
: impervious
Synonyms of impermeable
Examples of impermeable in a Sentence
an impermeable layer of rock
a fabric impermeable to moisture
Recent Examples on the Web
My father’s 1930s interviews tell stories of couples who defied Chicago’s seemingly impermeable color line.
—
Dorothy Roberts, Time, 13 Feb. 2026
Driveway materials can be impermeable or permeable—so traditional concrete and asphalt, or a pervious solution that allows rainwater to pass through.
—Alexandra Kelly, Martha Stewart, 9 Feb. 2026
The impermeable seed coat strategy generally helps survival of the species by making sure all of a season’s crop don’t germinate in the same year.
—Paul Cappiello, Louisville Courier Journal, 21 Nov. 2025
The discovery could enable large-scale use of impermeable coatings once limited by graphene’s scalability issues.
—Aamir Khollam, Interesting Engineering, 12 Nov. 2025
See All Example Sentences for impermeable
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Dorothy Roberts, Time, 13 Feb. 2026
Driveway materials can be impermeable or permeable—so traditional concrete and asphalt, or a pervious solution that allows rainwater to pass through.
—Alexandra Kelly, Martha Stewart, 9 Feb. 2026
The impermeable seed coat strategy generally helps survival of the species by making sure all of a season’s crop don’t germinate in the same year.
—Paul Cappiello, Louisville Courier Journal, 21 Nov. 2025
The discovery could enable large-scale use of impermeable coatings once limited by graphene’s scalability issues.
—Aamir Khollam, Interesting Engineering, 12 Nov. 2025
See All Example Sentences for impermeable
Cite this Entry
“Impermeable.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/impermeable. Accessed 14 Feb. 2026.
Copy CitationKids Definition
impermeable
adjective
im·per·me·able
(ˈ)im-ˈpər-mē-ə-bəl
: not permitting passage (as of a fluid) through the material of which it is made
Medical Definition
impermeable
adjective
im·per·me·able
(ˈ)im-ˈpər-mē-ə-bəl
: 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
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