quintillion

/kwɪnˈtɪljən/

//kwɪnˈtɪljən// num

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

The verdict

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

Unranked
below top-frequency English
11
letters

According to Wiktionary data (CC BY-SA, analyzed September 3, 2026) - Either of two very large amounts:

Corpus desk

Index EN-quintillion · quintillion · English

quintillion · unranked · 0 variants · 0 confusables

  • FREQ-UNRANKED Unranked
  • LEN-MEGA 11 letters
  • VOW-5 5 vowels
  • CONFUS-0 No pairs
  • VAR-0 0 variants
  • BOOK-THIN "Q" 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 quintillion
PropertyValue
Headwordquintillion
LanguageEnglish
Part of speechNumeral
IPA/kwɪnˈtɪljən/
Letters11
Misspellings tracked0
Confusable pairs0
SourceWiktionary (kaikki.org)

Long-tail rank of “quintillion” in English

quintillionsits 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

quintillion is uncommon English outside the top frequency list, classed as anumeral, transcribed /kwɪnˈtɪljən/. Rarity is why readers land here mid-draft. 3 senses are on record.

We couldn't generate a plausible misspelling set for quintillion, suggesting the orthography follows predictable English patterns. This entry stands alone in our confusable dataset, a sign it's visually distinctive enough not to be mixed up with another word.

Etymologically, the entry records: From French quintillion. By surface analysis, quint- (“five”) + -illion. The correct English form is quintillion, spelled Q-U-I-N-T-I-L-L-I-O-N.

Definition

  1. 1
    Either of two very large amounts:
  2. 2
    Either of two very large amounts:
  3. 3
    An unspecified very large number.

Recorded use

Wiktionary examples

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

  1. Last week, we used[…]the BBC News website's biggest number: 9,223,372,036,854,775,808, that's 9.2 quintillion[…][the maximum video viewer count on YouTube's] updated counter software.
  2. “I’m not sure I understand why we have to send a quadrillion-credit mission to another galaxy.” He looked fleetingly amused. “Quintillion... and we don’t have a choice, Harper. Any of us, really, but humanity especially.”

Etymology

From French quintillion. By surface analysis, quint- (“five”) + -illion.

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 "quintillion"?
"quintillion" is spelled Q-U-I-N-T-I-L-L-I-O-N. The IPA pronunciation is /kwɪnˈtɪljən/.
What does "quintillion" mean?
As a numeral, "quintillion" means: Either of two very large amounts:
How do you pronounce "quintillion"?
The IPA (International Phonetic Alphabet) transcription for "quintillion" is /kwɪnˈtɪljən/. 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 "quintillion"?
From French quintillion. By surface analysis, quint- (“five”) + -illion. 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