undeliverable

adj

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

"undeliverable" is a 13-letter English headword indexed on PlainSpell.

The verdict

“undeliverable” is uncommon English (frequency #94,383 among 1,433 “U” headwords), classed as an adjective. The kind of spelling people second-guess.

#94,383
frequency rank, English
1,433
“U” headwords

According to Wiktionary data (CC BY-SA, analyzed September 3, 2026) - Not able to be delivered.

Corpus desk

Index EN-undeliverable · undeliverable · English

undeliverable · rank #94,383 · 0 variants · 0 confusables

  • FREQ-RARE #94,383
  • LEN-MEGA 13 letters
  • VOW-6 6 vowels
  • CONFUS-0 No pairs
  • VAR-0 0 variants
  • BOOK-MID 1,433
  • PHOTO-FINISH unction

Nearest frequency peer: unction (-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 “undeliverable”

Sparse band: bars invert rank so rarer forms read shorter

corpus weight

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

Source FrequencyWords open word-frequency list As of September 3, 2026
Key facts for undeliverable
PropertyValue
Headwordundeliverable
LanguageEnglish
Part of speechAdjective
Letters13
Frequency rank#94,383
Misspellings tracked0
Confusable pairs0
SourceWiktionary (kaikki.org)

Long-tail rank of “undeliverable” in English

Every-word frequency runs from the handful of words we use constantly (left) to the long tail used once in a blue moon (right).undeliverablefalls 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: “unction” (#94,382), “understudied” (#94,384), “unbox” (#94,381). Among 1,433 “U” headwords, “undeliverable” is #94,383. Source: FrequencyWords open word-frequency list.

Rare enough to double-check

undeliverable is uncommon English at frequency #94,383 among 1,433 “U” headwords, classed as anadjective. Rarity is why readers land here mid-draft. Gloss: "Not able to be delivered.".

undeliverable doesn't appear in our generated misspelling index, a sign its spelling follows regular English conventions. It is not paired with a close-neighbour confusable in our dataset, since no other headword is close enough in sound or shape to pair with it.

Etymologically, the entry records: From un- + deliverable. The correct English form is undeliverable, spelled U-N-D-E-L-I-V-E-R-A-B-L-E.

Definition

  1. 1
    Not able to be delivered.

Recorded use

Wiktionary examples

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

  1. The dead letter office keeps undeliverable mail.
  2. The ambitious project to build 500 new hospitals was later deemed to be undeliverable.

Etymology

From un- + deliverable.

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 "undeliverable"?
"undeliverable" is spelled U-N-D-E-L-I-V-E-R-A-B-L-E.
What does "undeliverable" mean?
As an adjective, "undeliverable" means: Not able to be delivered.
What is the origin of the word "undeliverable"?
From un- + deliverable. 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 "undeliverable", not the corpus desk frequency band.

Same letter count

Frequency-ranked English headwords with 13 letters (nearest by frequency rank).

unmentionable#94,389unpasteurized#94,390streptococcal#94,290Schrödinger's#94,235

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

Source: FrequencyWords open word-frequency list