incombustible

/ˌɪŋkəmˈbʌstɪbəl/

//ˌɪŋkəmˈbʌstɪbəl// adj

"incombustible" is a 13-letter English headword indexed on PlainSpell.

The verdict

“incombustible” is uncommon English (outside the top frequency list), classed as an adjective. The kind of spelling people second-guess.

Unranked
below top-frequency English
13
letters

According to Wiktionary data (CC BY-SA, analyzed September 3, 2026) - Not capable of catching fire and burning; not flammable.

Corpus desk

Index EN-incombustible · incombustible · English

incombustible · unranked · 0 variants · 0 confusables

  • FREQ-UNRANKED Unranked
  • LEN-MEGA 13 letters
  • VOW-5 5 vowels
  • CONFUS-0 No pairs
  • VAR-0 0 variants
  • BOOK-THIN "I" thin
  • PHOTO-UNK Peer pending

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.

Key facts for incombustible
PropertyValue
Headwordincombustible
LanguageEnglish
Part of speechAdjective
IPA/ˌɪŋkəmˈbʌstɪbəl/
Letters13
Misspellings tracked0
Confusable pairs0
SourceWiktionary (kaikki.org)

Long-tail rank of “incombustible” in English

incombustiblesits beyond the 100,000 most-frequent English words, in the long tail of technical, archaic, or otherwise rare vocabulary where spelling doubt tends to strike hardest.

Beyond rank #100,000. Source: FrequencyWords open word-frequency list.

Rare enough to double-check

incombustible is uncommon English outside the top frequency list, classed as anadjective, transcribed /ˌɪŋkəmˈbʌstɪbəl/. Rarity is why readers land here mid-draft. Gloss: "Not capable of catching fire and burning; not flammable.".

incombustible has no tracked misspelling variants, which points to an orthography that plays by predictable English rules. This headword has no recorded confusable partner, since no other headword is close enough in sound or shape to pair with it.

Etymologically, the entry records: From in- + combust + -ible. The correct English form is incombustible, spelled I-N-C-O-M-B-U-S-T-I-B-L-E.

Definition

  1. 1
    Not capable of catching fire and burning; not flammable.

Recorded use

Wiktionary example

These source excerpts show how incombustible appears in context. They illustrate usage; the definition above remains the entry’s reference meaning.

  1. The ash represents the more incombustible mineral matter, usually of the nature of clay or slate.

Etymology

From in- + combust + -ible.

Antonyms

This word in other languages

Definitions, pronunciation, and etymology for this entry are drawn from Wiktionary via the kaikki.org structured extract (CC BY-SA). See the methodology for how each field is sourced and updated.

Frequently Asked Questions

How do you spell "incombustible"?
"incombustible" is spelled I-N-C-O-M-B-U-S-T-I-B-L-E. The IPA pronunciation is /ˌɪŋkəmˈbʌstɪbəl/.
What does "incombustible" mean?
As an adjective, "incombustible" means: Not capable of catching fire and burning; not flammable.
How do you pronounce "incombustible"?
The IPA (International Phonetic Alphabet) transcription for "incombustible" is /ˌɪŋkəmˈbʌstɪbəl/. 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 "incombustible"?
From in- + combust + -ible. 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.

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

Source: FrequencyWords open word-frequency list