impermeable

C2+ Topic:Describing Qualities

US /ɪmˈpɜrmiəbəl/ UK /ɪmˈpɜːmiəbəl/ See IPA manual

Meanings

1

adj
not allowing fluid to pass through

The clay layer is impermeable to groundwater.

Thesaurus

Synonyms

1 adj · not allowing fluid to pass... imperviouswatertightsealed impenetrablenonporousresistant

Opposites

permeable porous pervious penetrable

Word family

Derived forms impermeablyimpermeabilityimpermeableness

Related forms permeable permeate permeation

Etymology

From Late Latin impermeabilis, from in- ('not') + permeabilis ('passable'), from permeare ('to pass through'), from per- ('through') + meare ('to go, pass').

impermeabilis Latin meare Latin

View etymology graph ->

Topics

Describing Qualities Word Formation & Derivatives

External links

# impermeable

**Type:** Word
**Level:** C2+
**Part of speech:** adj
**IPA (US):** /ɪmˈpɜrmiəbəl/
**IPA (UK):** /ɪmˈpɜːmiəbəl/

## Meanings
1. not allowing fluid to pass through

## Examples
- The clay layer is impermeable to groundwater.

## Synonyms
- impervious
- watertight
- sealed
- impenetrable
- nonporous
- resistant

## Antonyms
- permeable
- porous
- pervious
- penetrable

## Derived Forms
- impermeably
- impermeability
- impermeableness

## Related Forms
- permeable
- permeate
- permeation

## Roots and Affixes
- Root: impermeabilis
- Root: meare

## Etymology
From Late Latin impermeabilis, from in- ('not') + permeabilis ('passable'), from permeare ('to pass through'), from per- ('through') + meare ('to go, pass').

## AI Etymology
impermeable comes from Late Latin impermeabilis, from in- ('not') + permeabilis ('passable'), from permeare ('to pass through'), from per- ('through') + meare ('to go, pass'). Morphologically, the prefixed shape matters: the initial element belongs to the recorded formation and helps explain the modern form's surface analysis. In present English, the adjective sense is "not allowing fluid to pass through", so the historical development ends in a clearly identifiable modern dictionary use. The same base also appears in related forms such as permeable, permeate, and permeation, and in derivatives such as impermeably, impermeability, and impermeableness. Its semantic neighborhood includes impervious, watertight, sealed, and impenetrable, which helps locate the modern sense without adding a separate etymological claim. The named historical forms include Latin impermeabilis and Latin meare.

## Topics
- Describing Qualities
- Word Formation & Derivatives

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