infirmity

/ɪnˈfɜːmɪti/

//ɪnˈfɜːmɪti// noun

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

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

The verdict

“infirmity” is uncommon English (frequency #65,208 among 2,140 “I” headwords), classed as a noun. The kind of spelling people second-guess.

#65,208
frequency rank, English
2,140
“I” headwords

According to Wiktionary data (CC BY-SA, analyzed September 3, 2026) - Feebleness, frailty or ailment, especially due to old age.

Corpus desk

Index EN-infirmity · infirmity · English

infirmity · rank #65,208 · 0 variants · 0 confusables

  • FREQ-RARE #65,208
  • LEN-LONG 9 letters
  • VOW-4 4 vowels
  • CONFUS-0 No pairs
  • VAR-0 0 variants
  • BOOK-MID 2,140
  • PHOTO-FINISH incompleteness

Nearest frequency peer: incompleteness (-2 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 “infirmity”

Sparse band: bars invert rank so rarer forms read shorter

corpus weight

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

Source FrequencyWords open word-frequency list As of September 3, 2026
Key facts for infirmity
PropertyValue
Headwordinfirmity
LanguageEnglish
Part of speechNoun
IPA/ɪnˈfɜːmɪti/
Letters9
Frequency rank#65,208
Misspellings tracked0
Confusable pairs0
SourceWiktionary (kaikki.org)

Long-tail rank of “infirmity” 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).infirmityfalls in this rarity band:

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

The axis is logarithmic, with each marked tick roughly ten times rarer than the last. Rare peers in the same band: “incompleteness” (#65,206), “incoherence” (#65,205), “impudence” (#65,204). Among 2,140 “I” headwords, “infirmity” is #65,208. Source: FrequencyWords open word-frequency list.

Rare enough to double-check

infirmity is uncommon English at frequency #65,208 among 2,140 “I” headwords, classed as anoun, transcribed /ɪnˈfɜːmɪti/. Rarity is why readers land here mid-draft. 2 senses are on record.

Our edit-distance generator produced no likely misspellings for infirmity, and the word's spelling is regular enough that our generator found nothing worth flagging. No close-neighbour confusable shows up for this headword in our dataset, a sign it's visually distinctive enough not to be mixed up with another word.

Etymologically, the entry records: From infirm + -ity. The correct English form is infirmity, spelled I-N-F-I-R-M-I-T-Y.

Definition

  1. 1
    Feebleness, frailty or ailment, especially due to old age.
  2. 2
    A moral weakness or defect.

Recorded use

Wiktionary examples

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

  1. physical infirmity
  2. mental infirmity

Etymology

From infirm + -ity.

This word in other languages

enfermedad(Español)infirmité(Français)Gebrechlichkeit(Deutsch)

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 "infirmity"?
"infirmity" is spelled I-N-F-I-R-M-I-T-Y. The IPA pronunciation is /ɪnˈfɜːmɪti/.
What does "infirmity" mean?
As a noun, "infirmity" means: Feebleness, frailty or ailment, especially due to old age.
How do you pronounce "infirmity"?
The IPA (International Phonetic Alphabet) transcription for "infirmity" is /ɪnˈfɜːmɪti/. Click the speaker icon on the pronunciation badge above to hear it spoken aloud where audio is available.
What is the origin of the word "infirmity"?
From infirm + -ity. 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 "infirmity", not the corpus desk frequency band.

Same letter count

Frequency-ranked English headwords with 9 letters (nearest by frequency rank).

impudence#65,204inshallah#65,212internist#65,213impassive#65,201

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

Source: FrequencyWords open word-frequency list