adjoint

/ˈæd͡ʒ.ɔɪnt/

//ˈæd͡ʒ.ɔɪnt// adj

By · According to Wiktionary data (CC BY-SA) ·

"adjoint" is a 7-letter English headword indexed on PlainSpell.

The verdict

“adjoint” is uncommon English (frequency #65,669 among 3,931 “A” headwords), classed as an adjective. The kind of spelling people second-guess.

#65,669
frequency rank, English
3,931
“A” headwords

According to Wiktionary data (CC BY-SA, analyzed September 3, 2026) - Used in certain contexts, in each case involving a pair of transformations, one of which is, or is analogous to, conjugation (either inner automorphism or complex conjugation).

Corpus desk

Index EN-adjoint · adjoint · English

adjoint · rank #65,669 · 0 variants · 0 confusables

  • FREQ-RARE #65,669
  • LEN-LONG 7 letters
  • VOW-3 3 vowels
  • CONFUS-0 No pairs
  • VAR-0 0 variants
  • BOOK-MID 3,931
  • PHOTO-FINISH adroit

Nearest frequency peer: adroit (+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 “adjoint”

Sparse band: bars invert rank so rarer forms read shorter

corpus weight

What this shows Long-tail view: where “adjoint” sits against similarly uncommon English ranks.

Source FrequencyWords open word-frequency list As of September 3, 2026
Key facts for adjoint
PropertyValue
Headwordadjoint
LanguageEnglish
Part of speechAdjective
IPA/ˈæd͡ʒ.ɔɪnt/
Letters7
Frequency rank#65,669
Misspellings tracked0
Confusable pairs0
SourceWiktionary (kaikki.org)

Long-tail rank of “adjoint” in English

This scale runs from the tiny cluster of words that carry ordinary speech (left) to the long tail of words almost nobody reaches for (right).adjointfalls in this rarity band:

#1#100#1K#10K#100K
← used constantlyrarely used →

Scale is logarithmic (each tick is 10× rarer). Rare peers in the same band: “adroit” (#65,671), “acerbic” (#65,666), “ablative” (#65,664). Among 3,931 “A” headwords, “adjoint” is #65,669. Source: FrequencyWords open word-frequency list.

Rare enough to double-check

adjoint is uncommon English at frequency #65,669 among 3,931 “A” headwords, classed as anadjective, transcribed /ˈæd͡ʒ.ɔɪnt/. Rarity is why readers land here mid-draft. 3 senses are on record.

Zero misspellings are on record for adjoint in our index, since its letter sequence doesn't invite the usual edit-distance slips. Our confusable-pair dataset has no match for it, which tends to mean the word is visually distinctive enough to stand on its own.

Etymologically, the entry records: From French adjoindre (“to join”), from late 19th C; see also adjoin. Doublet of adjunct. In the case of category theory (which brings together concepts from numerous fields), the term is often confounded with adjunct and the relationship is called an adjun… The correct English form is adjoint, spelled A-D-J-O-I-N-T.

Definition

  1. 1
    Used in certain contexts, in each case involving a pair of transformations, one of which is, or is analogous to, conjugation (either inner automorphism or complex conjugation).
  2. 2
    That is related to another functor by an adjunction.
  3. 3
    Having a relationship of the nature of an adjoint (adjoint curve); sharing multiple points with.

Recorded use

Wiktionary examples

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

  1. The sets A + A₀, B + B₀, together, form the complete intersection, with f = 0, of a composite adjoint curve of order m + k, consisting of the adjoint curve of order m through A + B, together with the non-adjoint curve ω = 0; and the set B + B₀ consists of p points, and lies on i + j adjoint φ-curves of f = 0.
  2. As we have stated before, a curve f' is adjoint to a curve f if it have at least the multiplicity r#95;i-1 at each point where f has the multiplicity r#95;i. A first polar #92;sum#95;iy#95;i#92;left(#92;partialf#47;#92;partialx#95;i#92;right)#61;0 is an example of an adjoint curve.

Etymology

From French adjoindre (“to join”), from late 19th C; see also adjoin. Doublet of adjunct. In the case of category theory (which brings together concepts from numerous fields), the term is often confounded with adjunct and the relationship is called an adjunction. The origin of any particular usage may therefore be uncertain.

Synonyms

adjunct

This word in other languages

adjunta(Español)adjungiert(Deutsch)

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

How do you spell "adjoint"?
"adjoint" is spelled A-D-J-O-I-N-T. The IPA pronunciation is /ˈæd͡ʒ.ɔɪnt/.
What does "adjoint" mean?
As an adjective, "adjoint" means: Used in certain contexts, in each case involving a pair of transformations, one of which is, or is analogous to, conjugation (either inner automorphism or complex conjugation).
How do you pronounce "adjoint"?
The IPA (International Phonetic Alphabet) transcription for "adjoint" is /ˈæd͡ʒ.ɔɪnt/. 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 "adjoint"?
From French adjoindre (“to join”), from late 19th C; see also adjoin. Doublet of adjunct. In the case of category theory (which brings together concepts from numerous fields), the term is often confounded with adjunct and the relationship is calle... 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.

Similar English words by spelling shape

Same letter count and similar misspelling depth for "adjoint", not the corpus desk frequency band.

Same letter count

Frequency-ranked English headwords with 7 letters (nearest by frequency rank).

acerbic#65,666airhead#65,678airless#65,679Amistad#65,684

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

Source: FrequencyWords open word-frequency list