indefatigable
/ˌɪn.dɪˈfæt.ɪ.ɡə.bəl/
"indefatigable" is a 13-letter English headword indexed on PlainSpell.
The verdict
“indefatigable” is uncommon English (frequency #50,002 among 2,140 “I” headwords), classed as an adjective. The kind of spelling people second-guess.
- #50,002
- frequency rank, English
- 2,140
- “I” headwords
According to Wiktionary data (CC BY-SA, analyzed September 3, 2026) - Extremely persistent and untiring.
Corpus desk
Index EN-indefatigable · indefatigable · English
indefatigable · rank #50,002 · 0 variants · 0 confusables
- FREQ-RARE #50,002
- LEN-MEGA 13 letters
- VOW-6 6 vowels
- CONFUS-0 No pairs
- VAR-0 0 variants
- BOOK-MID 2,140
- PHOTO-FINISH individualist
Nearest frequency peer: individualist (+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 “indefatigable”
Sparse band: bars invert rank so rarer forms read shorter
- illegible
illegible
50,004 corpus weight
- immunologic…
immunological
50,002 corpus weight
- impertinent
impertinent
50,001 corpus weight
- indefatigab…
indefatigable
49,999 corpus weight
- individuali…
individualist
49,998 corpus weight
- instrumenta…
instrumentalist
49,995 corpus weight
What this shows Long-tail view: where “indefatigable” sits against similarly uncommon English ranks.
| Property | Value |
|---|---|
| Headword | indefatigable |
| Language | English |
| Part of speech | Adjective |
| IPA | /ˌɪn.dɪˈfæt.ɪ.ɡə.bəl/ |
| Letters | 13 |
| Frequency rank | #50,002 |
| Misspellings tracked | 0 |
| Confusable pairs | 0 |
| Source | Wiktionary (kaikki.org) |
Long-tail rank of “indefatigable” in English
Rare enough to double-check
indefatigable is uncommon English at frequency #50,002 among 2,140 “I” headwords, classed as anadjective, transcribed /ˌɪn.dɪˈfæt.ɪ.ɡə.bəl/. Rarity is why readers land here mid-draft. Gloss: "Extremely persistent and untiring.".
Our edit-distance generator produced no likely misspellings for indefatigable, suggesting the orthography follows predictable English patterns. Our confusable-pair dataset has no match for it, which tends to mean the word is visually distinctive enough to stand on its own.
Etymologically, the entry records: From Middle French, from Latin indēfatīgābilis (“untiring”), from in- (“not”) + dēfatīgō (“to tire out”). The correct English form is indefatigable, spelled I-N-D-E-F-A-T-I-G-A-B-L-E.
Definition
- 1Extremely persistent and untiring.
Recorded use
Wiktionary examplesThese source excerpts show how indefatigable appears in context. They illustrate usage; the definition above remains the entry’s reference meaning.
[...] But he was at the ſame Time an excellent Scholar, and moſt indefatigable in teaching the two Lads.
He was respected by all who knew him for his integrity and indefatigable attention to public business.
Etymology
From Middle French, from Latin indēfatīgābilis (“untiring”), from in- (“not”) + dēfatīgō (“to tire out”).
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
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Similar English words by spelling shape
Same letter count and similar misspelling depth for "indefatigable", not the corpus desk frequency band.
Same letter count
Frequency-ranked English headwords with 13 letters (nearest by frequency rank).