impermeable

/ɪmˈpɜːmɪəbəl/

//ɪmˈpɜːmɪəbəl// adj

By · According to Wiktionary data (CC BY-SA) ·

"impermeable" is a 11-letter English headword indexed on PlainSpell.

The verdict

“impermeable” is uncommon English (frequency #57,451 among 2,140 “I” headwords), classed as an adjective. The kind of spelling people second-guess.

#57,451
frequency rank, English
2,140
“I” headwords

According to Wiktionary data (CC BY-SA, analyzed September 3, 2026) - Impossible to permeate.

Corpus desk

Index EN-impermeable · impermeable · English

impermeable · rank #57,451 · 0 variants · 0 confusables

  • FREQ-RARE #57,451
  • LEN-MEGA 11 letters
  • VOW-5 5 vowels
  • CONFUS-0 No pairs
  • VAR-0 0 variants
  • BOOK-MID 2,140
  • PHOTO-FINISH impartially

Nearest frequency peer: impartially (-1 rank slots)

Read with this headword: Spelling guide for this pattern

Desk codes from Wiktionary headword shape, FrequencyWords rank tier, confusable-pair count, generated misspelling depth, letter-cohort book size, and photo-finish peer. Not a difficulty grade.

Long-tail ranks near “impermeable”

Sparse band: bars invert rank so rarer forms read shorter

corpus weight

What this shows Long-tail view: where “impermeable” sits against similarly uncommon English ranks.

Source FrequencyWords open word-frequency list As of September 3, 2026
Key facts for impermeable
PropertyValue
Headwordimpermeable
LanguageEnglish
Part of speechAdjective
IPA/ɪmˈpɜːmɪəbəl/
Letters11
Frequency rank#57,451
Misspellings tracked0
Confusable pairs0
SourceWiktionary (kaikki.org)

Long-tail rank of “impermeable” in English

This scale runs from the tiny cluster of words that carry ordinary speech (left) to the long tail of words almost nobody reaches for (right).impermeablefalls in this rarity band:

#1#100#1K#10K#100K
← used constantlyrarely used →

The axis is logarithmic, with each marked tick roughly ten times rarer than the last. Rare peers in the same band: “impartially” (#57,450), “imbalanced” (#57,449), “imager” (#57,448). Among 2,140 “I” headwords, “impermeable” is #57,451. Source: FrequencyWords open word-frequency list.

Rare enough to double-check

impermeable is uncommon English at frequency #57,451 among 2,140 “I” headwords, classed as anadjective, transcribed /ɪmˈpɜːmɪəbəl/. Rarity is why readers land here mid-draft. 2 senses are on record.

impermeable has no tracked misspelling variants, since its letter sequence doesn't invite the usual edit-distance slips. No confusable counterpart is on file for this word, since no other headword is close enough in sound or shape to pair with it.

Etymologically, the entry records: Apparently from im- + permeable. Compare French imperméable, from Latin impermeābilis, from im- + permeābilis (“permeable”). The correct English form is impermeable, spelled I-M-P-E-R-M-E-A-B-L-E.

Definition

  1. 1
    Impossible to permeate.
  2. 2
    Not allowing passage, especially of liquids; waterproof.

Etymology

Apparently from im- + permeable. Compare French imperméable, from Latin impermeābilis, from im- + permeābilis (“permeable”).

Synonyms

nonpermeablesealed

Antonyms

permeable

This word in other languages

impermeable(Español)imperméable(Français)dicht(Deutsch)impermeável(Português)

Definitions, pronunciation, and etymology for this entry are drawn from Wiktionary via the kaikki.org structured extract (CC BY-SA); frequency ordering uses the FrequencyWords open word-frequency list (2018 English corpus, MIT). See the methodology for how each field is sourced and updated.

Frequently Asked Questions

How do you spell "impermeable"?
"impermeable" is spelled I-M-P-E-R-M-E-A-B-L-E. The IPA pronunciation is /ɪmˈpɜːmɪəbəl/.
What does "impermeable" mean?
As an adjective, "impermeable" means: Impossible to permeate.
How do you pronounce "impermeable"?
The IPA (International Phonetic Alphabet) transcription for "impermeable" is /ɪmˈpɜːmɪəbəl/. Click the speaker icon on the pronunciation badge above to hear it spoken aloud where audio is available.
What is the origin of the word "impermeable"?
Apparently from im- + permeable. Compare French imperméable, from Latin impermeābilis, from im- + permeābilis (“permeable”). See the full etymology section above for more details.
Is PlainSpell free to use?
Yes, PlainSpell is a completely free word reference. You can look up definitions, pronunciations, confusable pairs, homophones, and spelling corrections across 5 languages without any sign-up or subscription.

Similar English words by spelling shape

Same letter count and similar misspelling depth for "impermeable", not the corpus desk frequency band.

Same letter count

Frequency-ranked English headwords with 11 letters (nearest by frequency rank).

impartially#57,450heightening#57,423eschatology#57,374luminescent#57,531

Source: Wiktionary (via kaikki.org) Structured Wiktionary extract

Source: FrequencyWords open word-frequency list