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.

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impermeable British  

/ ɪmˈpɜːmɪəbəl /

adjective

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

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impermeable Scientific  

/ ĭm-pûr′mē-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.

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Other Word Forms

• impermeability noun
• impermeableness noun
• impermeably adverb

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:

• permeable vs. impermeable

Example Sentences

“Europe needs to make itself impermeable to every interference” by outside powers, whether the U.S. or Russia, he said.

From The Wall Street Journal • Jan. 19, 2026

Roberts said that Chiquita Canyon was far behind schedule with the installation of a large impermeable cover, which was intended to suppress odors.

From Los Angeles Times • Aug. 30, 2024

Prato demonstrated the method earlier this week outside the emergency department of Valleywise Health Medical Center in Phoenix, packing ice cubes inside an impermeable blue bag around a medical dummy representing a patient.

From Seattle Times • Jun. 4, 2024

When these holds prevent assistance from getting in to alleviate famine pressures – or prevent populations from leaving – they are highly impermeable.

From Salon • Apr. 30, 2024

They tie nkisis of leaves around their wrists and declare themselves impermeable to bullets, immune to death.

From "The Poisonwood Bible" by Barbara Kingsolver