cumulonimbus

/ˌkjuː.mjʊ.ləʊˈnɪm.bəs/

//ˌkjuː.mjʊ.ləʊˈnɪm.bəs// noun

"cumulonimbus" is a 12-letter English headword indexed on PlainSpell.

The verdict

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

Unranked
below top-frequency English
12
letters

According to Wiktionary data (CC BY-SA, analyzed September 3, 2026) - A cloud with a tall structure and flat base, often associated with thunderstorms.

Corpus desk

Index EN-cumulonimbus · cumulonimbus · English

cumulonimbus · unranked · 0 variants · 0 confusables

  • FREQ-UNRANKED Unranked
  • LEN-MEGA 12 letters
  • VOW-5 5 vowels
  • CONFUS-0 No pairs
  • VAR-0 0 variants
  • BOOK-THIN "C" 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 cumulonimbus
PropertyValue
Headwordcumulonimbus
LanguageEnglish
Part of speechNoun
IPA/ˌkjuː.mjʊ.ləʊˈnɪm.bəs/
Letters12
Misspellings tracked0
Confusable pairs0
SourceWiktionary (kaikki.org)

Long-tail rank of “cumulonimbus” in English

cumulonimbusfalls outside the top-100,000 ranked English words, the long-tail zone of technical, archaic, or low-frequency vocabulary, exactly where readers second-guess spellings most.

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

Rare enough to double-check

cumulonimbus is uncommon English outside the top frequency list, classed as anoun, transcribed /ˌkjuː.mjʊ.ləʊˈnɪm.bəs/. Rarity is why readers land here mid-draft. Gloss: "A cloud with a tall structure and flat base, often associated with thunderstorms.".

cumulonimbus has no tracked misspelling variants, a straightforward case of a spelling with little room for common typos. It is not paired with a close-neighbour confusable in our dataset, a sign it's visually distinctive enough not to be mixed up with another word.

Etymologically, the entry records: From Latin cumulus (“heap”) + nimbus (“cloud”). The correct English form is cumulonimbus, spelled C-U-M-U-L-O-N-I-M-B-U-S.

Definition

  1. 1
    A cloud with a tall structure and flat base, often associated with thunderstorms.

Recorded use

Wiktionary example

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

  1. The one to the east (which at the moment seemed to be leaping straight out of the heart of a sinister slaty-purple patch of cumulonimbus) drained the Lake of the Hanging Glaciers; that to the west a desolate rock and ice-walled valley which was rimmed by some of the highest summits in the Selkirks.

Etymology

From Latin cumulus (“heap”) + nimbus (“cloud”).

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 "cumulonimbus"?
"cumulonimbus" is spelled C-U-M-U-L-O-N-I-M-B-U-S. The IPA pronunciation is /ˌkjuː.mjʊ.ləʊˈnɪm.bəs/.
What does "cumulonimbus" mean?
As a noun, "cumulonimbus" means: A cloud with a tall structure and flat base, often associated with thunderstorms.
How do you pronounce "cumulonimbus"?
The IPA (International Phonetic Alphabet) transcription for "cumulonimbus" is /ˌkjuː.mjʊ.ləʊˈnɪm.bəs/. 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 "cumulonimbus"?
From Latin cumulus (“heap”) + nimbus (“cloud”). 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