ket
/kɛt/
"ket" is a 3-letter English headword indexed on PlainSpell.
The verdict
“ket” is uncommon English (frequency #50,025 among 1,236 “K” headwords), classed as a noun. The kind of spelling people second-guess.
- #50,025
- frequency rank, English
- 1,236
- “K” headwords
According to Wiktionary data (CC BY-SA, analyzed September 3, 2026) - A column vector, in Hilbert space, especially as representing the state of a quantum mechanical system; the complex conjugate transpose of a bra (a row vector); a ket vector. Symbolised by |...〉.
Corpus desk
Index EN-ket · ket · English
ket · rank #50,025 · 0 variants · 0 confusables
- FREQ-RARE #50,025
- LEN-MID 3 letters
- VOW-1 1 vowel
- CONFUS-0 No pairs
- VAR-0 0 variants
- BOOK-MID 1,236
- PHOTO-FINISH Kenai
Nearest frequency peer: Kenai (-2 rank slots)
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.
Long-tail ranks near “ket”
Sparse band: bars invert rank so rarer forms read shorter
- Kabbalah
Kabbalah
49,980 corpus weight
- Kanter
Kanter
49,979 corpus weight
- Kenai
Kenai
49,978 corpus weight
- ket
ket
49,976 corpus weight
- Kovacs
Kovacs
49,974 corpus weight
- krazy
krazy
49,973 corpus weight
What this shows Long-tail view: where “ket” sits against similarly uncommon English ranks.
| Property | Value |
|---|---|
| Headword | ket |
| Language | English |
| Part of speech | Noun |
| IPA | /kɛt/ |
| Letters | 3 |
| Frequency rank | #50,025 |
| Misspellings tracked | 0 |
| Confusable pairs | 0 |
| Source | Wiktionary (kaikki.org) |
Long-tail rank of “ket” in English
Rare enough to double-check
ket is uncommon English at frequency #50,025 among 1,236 “K” headwords, classed as anoun, transcribed /kɛt/. Rarity is why readers land here mid-draft. Gloss: "A column vector, in Hilbert space, especially as representing the state of a quantum mechanical system; the complex conjugate transpose of a bra (a row vector); a ket vector. Symbolised by |...〉.".
Zero misspellings are on record for ket in our index, since its letter pattern doesn't lend itself to common typo substitutions. Our dataset records no confusable match here, which tends to mean the word is visually distinctive enough to stand on its own.
Etymologically, the entry records: From bra-ket notation invented by Paul Dirac, from bracket. The correct English form is ket, spelled K-E-T.
Definition
- 1A column vector, in Hilbert space, especially as representing the state of a quantum mechanical system; the complex conjugate transpose of a bra (a row vector); a ket vector. Symbolised by |...〉.
Recorded use
Wiktionary exampleThese source excerpts show how ket appears in context. They illustrate usage; the definition above remains the entry’s reference meaning.
A particular ket, say #124;A#92;rangle, might be represented by a particular column vector. Its corresponding bra, #92;langleA#124;, would then be represented by the row vector which is the transpose conjugate of that column vector.
Etymology
From bra-ket notation invented by Paul Dirac, from bracket.
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); frequency ordering uses the FrequencyWords open word-frequency list (2018 English corpus, MIT). See the methodology for how each field is sourced and updated.
Frequently Asked Questions
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Similar English words by spelling shape
Same letter count and similar misspelling depth for "ket", not the corpus desk frequency band.
Same letter count
Frequency-ranked English headwords with 3 letters (nearest by frequency rank).