unheard-of

adj

"unheard-of" is a 9-letter English headword indexed on PlainSpell.

The verdict

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

Unranked
below top-frequency English
10
letters

According to Wiktionary data (CC BY-SA, analyzed September 3, 2026) - Previously unknown; unprecedented.

Corpus desk

Index EN-unheard-of · unheard-of · English

unheard-of · unranked · 0 variants · 0 confusables

  • FREQ-UNRANKED Unranked
  • LEN-MEGA 10 letters
  • VOW-4 4 vowels
  • CONFUS-0 No pairs
  • VAR-0 0 variants
  • BOOK-THIN "U" 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 unheard-of
PropertyValue
Headwordunheard-of
LanguageEnglish
Part of speechAdjective
Letters10
Misspellings tracked0
Confusable pairs0
SourceWiktionary (kaikki.org)

Long-tail rank of “unheard-of” in English

unheard-offalls outside the top-100,000 ranked English words, the long-tail zone of technical, archaic, or low-frequency vocabulary, exactly where readers second-guess spellings most.

Beyond rank #100,000. Source: FrequencyWords open word-frequency list.

Rare enough to double-check

unheard-of is uncommon English outside the top frequency list, classed as anadjective. Rarity is why readers land here mid-draft. Gloss: "Previously unknown; unprecedented.".

Zero misspellings are on record for unheard-of in our index, a straightforward case of a spelling with little room for common typos. We don't track a confusable pairing for this entry, suggesting its spelling stands apart enough that readers rarely confuse it with something else.

This entry carries no recorded etymology, so its spelling is best read as a straightforward mapping from sound to letter. The correct English form is unheard-of, spelled U-N-H-E-A-R-D---O-F.

Definition

  1. 1
    Previously unknown; unprecedented.

Recorded use

Wiktionary examples

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

  1. He was […] none of your unconscionable blades, requiring impossible chops, and taking unheard-of pickles for granted.
  2. Starvation in the uplands was not an unheard-of thing; […]

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 "unheard-of"?
"unheard-of" is spelled U-N-H-E-A-R-D---O-F.
What does "unheard-of" mean?
As an adjective, "unheard-of" means: Previously unknown; unprecedented.
What language does "unheard-of" come from?
"unheard-of" is a English word. PlainSpell covers definitions, pronunciations, and spelling data across English, Spanish, Portuguese, French, and German.
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