ket
/kɛt/
"ket" is a 3-letter English headword indexed on PlainSpell.
The verdict
“ket” is uncommon English (frequency #50,025 among 9,255 “K” headwords), classed as a noun. The kind of spelling people second-guess.
- #50,025
- frequency rank, English
- 9,255
- “K” headwords
According to Wiktionary data (CC BY-SA, analyzed May 6, 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 |...〉.
| 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) |
Where “ket” sits in English frequency
Rare enough to double-check
ket is uncommon English at frequency #50,025 among 9,255 “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 |...〉.
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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Using “ket”
The practical upshot for anyone who landed here from a spell-check.
- The one correct English spelling is K-E-T - every other letter order is a misspelling in standard orthography.
- Say it as /kɛt/ (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
Other uncommon English words near this rank
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.