treacherousness

noun

"treacherousness" is a 15-letter English headword indexed on PlainSpell.

The verdict

“treacherousness” is uncommon English (outside the top frequency list), classed as a noun. The kind of spelling people second-guess.

Unranked
below top-frequency English
15
letters

According to Wiktionary data (CC BY-SA, analyzed September 3, 2026) - Treachery; the characteristic of being treacherous.

Corpus desk

Index EN-treacherousness · treacherousness · English

treacherousness · unranked · 0 variants · 0 confusables

  • FREQ-UNRANKED Unranked
  • LEN-MEGA 15 letters
  • VOW-6 6 vowels
  • CONFUS-0 No pairs
  • VAR-0 0 variants
  • BOOK-THIN "T" 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 treacherousness
PropertyValue
Headwordtreacherousness
LanguageEnglish
Part of speechNoun
Letters15
Misspellings tracked0
Confusable pairs0
SourceWiktionary (kaikki.org)

Long-tail rank of “treacherousness” in English

treacherousnesssits 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

treacherousness is uncommon English outside the top frequency list, classed as anoun. Rarity is why readers land here mid-draft. Gloss: "Treachery; the characteristic of being treacherous.".

Zero misspellings are on record for treacherousness in our index, since its letter pattern doesn't lend itself to common typo substitutions. Our confusable-pair dataset has no match for it, which usually means its spelling is distinct enough that readers don't reach for a similar-looking word instead.

Etymologically, the entry records: From treacherous + -ness. The correct English form is treacherousness, spelled T-R-E-A-C-H-E-R-O-U-S-N-E-S-S.

Definition

  1. 1
    Treachery; the characteristic of being treacherous.

Recorded use

Wiktionary example

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

  1. He had an aggressive treacherousness of eye which his potations had not subdued.

Etymology

From treacherous + -ness.

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 "treacherousness"?
"treacherousness" is spelled T-R-E-A-C-H-E-R-O-U-S-N-E-S-S.
What does "treacherousness" mean?
As a noun, "treacherousness" means: Treachery; the characteristic of being treacherous.
What is the origin of the word "treacherousness"?
From treacherous + -ness. 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