indeclinable

adj

"indeclinable" is a 12-letter English headword indexed on PlainSpell.

The verdict

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

Unranked
below top-frequency English
12
letters

According to Wiktionary data (CC BY-SA, analyzed September 3, 2026) - That one cannot decline; unavoidable.

Corpus desk

Index EN-indeclinable · indeclinable · English

indeclinable · unranked · 0 variants · 0 confusables

  • FREQ-UNRANKED Unranked
  • LEN-MEGA 12 letters
  • VOW-5 5 vowels
  • CONFUS-0 No pairs
  • VAR-0 0 variants
  • BOOK-THIN "I" 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 indeclinable
PropertyValue
Headwordindeclinable
LanguageEnglish
Part of speechAdjective
Letters12
Misspellings tracked0
Confusable pairs0
SourceWiktionary (kaikki.org)

Long-tail rank of “indeclinable” in English

indeclinablesits 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

indeclinable is uncommon English outside the top frequency list, classed as anadjective. Rarity is why readers land here mid-draft. 2 senses are on record.

indeclinable has no tracked misspelling variants, since its letter sequence doesn't invite the usual edit-distance slips. We don't track a confusable pairing for this entry, since no other headword is close enough in sound or shape to pair with it.

Etymologically, the entry records: From French indéclinable, from Middle French, from Latin indeclinabilis. Equivalent to in- + declinable. The correct English form is indeclinable, spelled I-N-D-E-C-L-I-N-A-B-L-E.

Definition

  1. 1
    That one cannot decline; unavoidable.
  2. 2
    Not grammatically declinable; of a word, having no inflections.

Recorded use

Wiktionary example

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

  1. He'd planned to work a double shift Friday night, but Gladys Silverman's indeclinable invitation threw a hefty wrench into David's plans.

Etymology

From French indéclinable, from Middle French, from Latin indeclinabilis. Equivalent to in- + declinable.

Synonyms

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 "indeclinable"?
"indeclinable" is spelled I-N-D-E-C-L-I-N-A-B-L-E.
What does "indeclinable" mean?
As an adjective, "indeclinable" means: That one cannot decline; unavoidable.
What is the origin of the word "indeclinable"?
From French indéclinable, from Middle French, from Latin indeclinabilis. Equivalent to in- + declinable. 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