number one
"number-one" is a 9-letter English headword indexed on PlainSpell.
The verdict
“number one” is outside the top-ranked English vocabulary, used as an adjective - the kind of word writers most often double-check.
- Unranked
- below top-frequency English
- 10
- letters
According to Wiktionary data (CC BY-SA, analyzed May 6, 2026) - First; foremost; best, often used after its headword.
| Property | Value |
|---|---|
| Headword | number one |
| Language | English |
| Part of speech | Adjective |
| Letters | 10 |
| Misspellings tracked | 0 |
| Confusable pairs | 0 |
| Source | Wiktionary (kaikki.org) |
Where “number one” sits in English frequency
Spelling & Dictionary Insight
The English entry for number one is 10 letters long, classified as an adjective. It sits outside the most-frequent rank tiers, which is often why uncommon words generate more spelling variants per reader. Wiktionary records 2 distinct senses for this headword, so context determines which meaning a reader should apply.
We couldn't generate a plausible misspelling set for number one, suggesting the orthography follows predictable English patterns. No close-neighbour confusable shows up for this headword in our dataset, since its spelling is unusual enough that it doesn't cluster with a lookalike.
Etymologically, the entry records: Piecewise doublet of numero uno. The correct English form is number one, spelled N-U-M-B-E-R- -O-N-E.
Definition
- 1First; foremost; best, often used after its headword.
- 2Black, African-American.
Etymology
Piecewise doublet of numero uno.
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
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Using “number one”
The practical upshot for anyone who landed here from a spell-check.
- The one correct English spelling is N-U-M-B-E-R- -O-N-E - every other letter order is a misspelling in standard orthography.
- 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.