impermeable

1 of 2

adjective

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

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

broadly : impervious

impermeability

(ˌ)im-ˌpər-mē-ə-ˈbi-lə-tē 

noun

impermeability

2 of 2

noun

im·​permeability (¦)im 

əm+

: the quality or state of being impermeable

Synonyms of impermeable

Adjective

• impervious
• dense
• close
• impenetrable
• impassable
• impregnable
• thick

Examples of impermeable in a Sentence

Adjective

an impermeable layer of rock

a fabric impermeable to moisture

Recent Examples on the Web

Adjective

Spain needed until the 106th minute to slip a Ferran Torres shot past the impermeable goalkeeping of Argentina’s Emiliano Martínez, whose championship-game record 11 saves proved one too few. — Jerry Brewer, New York Times, 20 July 2026

Chocolate brown stripes punctuate a light charcoal gray background, and the low-pile weave made from recycled polyester gives it an impermeable, easy-to-clean surface. — Julia Harrison, Architectural Digest, 26 June 2026

Needing to remain impermeable to everything that is said about him is another stylistic exercise built into the equation of being a global star. — Time, Time, 26 June 2026

Engineers eventually replaced them with a version made up of 20 impermeable compartments of high-pressure hoses containing water. — Mack Degeurin, Popular Science, 18 June 2026

Word History

Etymology

Adjective

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

First Known Use

Adjective

1661, in the meaning defined above

Rhymes for impermeable

• permeable
• semipermeable

Kids 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

impermeability

(ˌ)im-ˌpər-mē-ə-ˈbil-ət-ē 

noun

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

impermeability

(ˌ)im-ˌpər-mē-ə-ˈbil-ət-ē 

noun

plural impermeabilities