unsub

/ˈʌnsʌb/

//ˈʌnsʌb// noun

"unsub" is a 5-letter English headword indexed on PlainSpell.

The verdict

“unsub” is uncommon English (frequency #56,511 among 1,433 “U” headwords), classed as a noun. The kind of spelling people second-guess.

#56,511
frequency rank, English
1,433
“U” headwords

According to Wiktionary data (CC BY-SA, analyzed September 3, 2026) - Abbreviation of unknown subject of an investigation..

Corpus desk

Index EN-unsub · unsub · English

unsub · rank #56,511 · 0 variants · 0 confusables

  • FREQ-RARE #56,511
  • LEN-MID 5 letters
  • VOW-2 2 vowels
  • CONFUS-0 No pairs
  • VAR-0 0 variants
  • BOOK-MID 1,433
  • PHOTO-FINISH unscrew

Nearest frequency peer: unscrew (-1 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 “unsub”

Sparse band: bars invert rank so rarer forms read shorter

corpus weight

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

Source FrequencyWords open word-frequency list As of September 3, 2026
Key facts for unsub
PropertyValue
Headwordunsub
LanguageEnglish
Part of speechNoun
IPA/ˈʌnsʌb/
Letters5
Frequency rank#56,511
Misspellings tracked0
Confusable pairs0
SourceWiktionary (kaikki.org)

Long-tail rank of “unsub” in English

Word frequency stretches from the small set of words we reach for constantly (left) out to the long tail barely used once in a while (right).unsubfalls in this rarity band:

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

Ticks step logarithmically, so each one marks a roughly tenfold drop in how often the word turns up. Rare peers in the same band: “unscrew” (#56,510), “valance” (#56,512), “unlearn” (#56,509). Among 1,433 “U” headwords, “unsub” is #56,511. Source: FrequencyWords open word-frequency list.

Rare enough to double-check

unsub is uncommon English at frequency #56,511 among 1,433 “U” headwords, classed as anoun, transcribed /ˈʌnsʌb/. Rarity is why readers land here mid-draft. Gloss: "Abbreviation of unknown subject of an investigation..".

The misspelling generator found no plausible variants for unsub, which points to an orthography that plays by predictable English rules. No confusable counterpart is on file for this word, which tends to mean the word is visually distinctive enough to stand on its own.

This entry's etymology isn't recorded, so its spelling pattern is best understood through pronunciation rather than a traceable origin. The correct English form is unsub, spelled U-N-S-U-B.

Definition

  1. 1
    Abbreviation of unknown subject of an investigation..

Recorded use

Wiktionary examples

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

  1. Further analysis may identify that the unsub has no specific schedule and has been escalating in the type of fire activity he or she is involved in.
  2. In short, UNSUB profiling is premised on two fundamental assumptions: (1) behavioral uniformity across offenses and (2) steady associations between configurations of offense behaviors and background characteristics.

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

How do you spell "unsub"?
"unsub" is spelled U-N-S-U-B. The IPA pronunciation is /ˈʌnsʌb/.
What does "unsub" mean?
As a noun, "unsub" means: Abbreviation of unknown subject of an investigation..
How do you pronounce "unsub"?
The IPA (International Phonetic Alphabet) transcription for "unsub" is /ˈʌnsʌb/. Click the speaker icon on the pronunciation badge above to hear it spoken aloud where audio is available.
What language does "unsub" come from?
"unsub" is a English word. PlainSpell's reference spans five languages -- English, Spanish, Portuguese, French, and German -- with definitions, pronunciations, and spelling data for each.
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 "unsub", not the corpus desk frequency band.

Same letter count

Frequency-ranked English headwords with 5 letters (nearest by frequency rank).

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

Source: FrequencyWords open word-frequency list