sui generis

/suˑ.i ˈɡɛnɛɹɪs/

//suˑ.i ˈɡɛnɛɹɪs// adj

"sui-generis" is a 10-letter English headword indexed on PlainSpell.

The verdict

“sui generis” is uncommon English (outside the top frequency list), classed as an adjective. 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) - In a class of its own; one of a kind.

Corpus desk

Index EN-sui-generis · sui generis · English

sui generis · 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 "S" 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 sui generis
PropertyValue
Headwordsui generis
LanguageEnglish
Part of speechAdjective
IPA/suˑ.i ˈɡɛnɛɹɪs/
Letters11
Misspellings tracked0
Confusable pairs0
SourceWiktionary (kaikki.org)

Long-tail rank of “sui generis” in English

sui generissits 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

sui generis is uncommon English outside the top frequency list, classed as anadjective, transcribed /suˑ.i ˈɡɛnɛɹɪs/. Rarity is why readers land here mid-draft. Gloss: "In a class of its own; one of a kind.".

No generated misspelling entries exist for sui generis in our index, which points to an orthography that plays by predictable English rules. No close-neighbour confusable shows up for this headword in our dataset, suggesting its spelling stands apart enough that readers rarely confuse it with something else.

Etymologically, the entry records: Borrowed from Latin suī generis (literally “of its own kind/class”). The correct English form is sui generis, spelled S-U-I- -G-E-N-E-R-I-S.

Definition

  1. 1
    In a class of its own; one of a kind.

Recorded use

Wiktionary examples

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

  1. It is easy to describe second-rate talents, because they fall into a class and enlist under a standard; but first-rate powers defy calculation or comparison, and can be defined only by themselves. They are sui generis, and make the class to which they belong.
  2. The transcendent case before us is absolutely sui generis.

Etymology

Borrowed from Latin suī generis (literally “of its own kind/class”).

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 "sui generis"?
"sui generis" is spelled S-U-I- -G-E-N-E-R-I-S. The IPA pronunciation is /suˑ.i ˈɡɛnɛɹɪs/.
What does "sui generis" mean?
As an adjective, "sui generis" means: In a class of its own; one of a kind.
How do you pronounce "sui generis"?
The IPA (International Phonetic Alphabet) transcription for "sui generis" is /suˑ.i ˈɡɛnɛɹɪs/. 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 "sui generis"?
Borrowed from Latin suī generis (literally “of its own kind/class”). 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