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 May 6, 2026) - A cloud with a tall structure and flat base, often associated with thunderstorms.

Key facts for cumulonimbus
PropertyValue
Headwordcumulonimbus
LanguageEnglish
Part of speechNoun
IPA/ˌkjuː.mjʊ.ləʊˈnɪm.bəs/
Letters12
Misspellings tracked0
Confusable pairs0
SourceWiktionary (kaikki.org)

Where “cumulonimbus” sits in English frequency

cumulonimbus falls 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.

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.

Using “cumulonimbus”

The practical upshot for anyone who landed here from a spell-check.

  • The one correct English spelling is C-U-M-U-L-O-N-I-M-B-U-S - every other letter order is a misspelling in standard orthography.
  • Say it as /ˌkjuː.mjʊ.ləʊˈnɪm.bəs/ (IPA); tap the speaker on the pronunciation badge to hear it where audio exists.
  • Browse more English words and confusable pairs in the same reference. English words
Data Source

Wiktionary (via kaikki.org), licensed under CC BY-SA & GFDL. Word ordering uses an open word-frequency list; misspelling variants are generated by edit-distance from the correct headword.

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

Source: FrequencyWords open word-frequency list