illness

/ˈɪl.nəs/

//ˈɪl.nəs// noun

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

"illness" is a 7-letter English headword indexed on PlainSpell.

The verdict

“illness” has 7 generated spelling variants in the English index at frequency #3,563. The variants make it a useful spelling check.

#3,563
frequency rank, English
2,140
“I” headwords
7
tracked misspellings
1
confusable pair

According to Wiktionary data (CC BY-SA, analyzed September 3, 2026) - An instance of a disease or poor health.

Corpus desk

Index EN-illness · illness · English

illness · rank #3,563 · 7 variants · 1 confusable

  • FREQ-COMMON #3,563
  • LEN-LONG 7 letters
  • VOW-2 2 vowels
  • CONFUS-LOW 1 pairs
  • VAR-MID 7 variants
  • BOOK-MID 2,140
  • PHOTO-FINISH hired

Nearest frequency peer: hired (-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.

Rank peers near misspelling magnet “illness”

Same rarity band: useful when a typo lands on a peer headword

corpus weight

What this shows “illness” sits among these FrequencyWords peers; misspelling depth is tracked separately in the edit-distance chart.

Source FrequencyWords open word-frequency list As of September 3, 2026

Visual similarity to commonly confused words

How many letter changes separate each confused pair (Levenshtein distance, normalized).

illness vs illnesses
78% similar

Source: PlainSpell confusable corpus (Wiktionary, CC BY-SA).

Key facts for illness
PropertyValue
Headwordillness
LanguageEnglish
Part of speechNoun
IPA/ˈɪl.nəs/
Letters7
Frequency rank#3,563
Misspellings tracked7
Confusable pairs1
SourceWiktionary (kaikki.org)

Frequency seat of misspelling magnet “illness”

This scale runs from the tiny cluster of words that carry ordinary speech (left) to the long tail of words almost nobody reaches for (right).illnesslands here:

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

The axis is logarithmic, with each marked tick roughly ten times rarer than the last. Same rarity band neighbours include “hired” (#3,562), “inspiration” (#3,564), “foods” (#3,561). Among 2,140 “I” headwords, “illness” is #3,563. Source: FrequencyWords open word-frequency list.

A misspelling magnet

The generator records 7 spelling variants around illness (IPA /ˈɪl.nəs/), anoun. Corpus frequency is #3,563 among 2,140 “I” headwords. Wiktionary lists 2 senses, so context still picks the gloss.

Our generated misspelling index lists 7 likely wrong-spelling variants for illness, with forms such as "illenss", "illnes", and "illnness". Each variant is a distinct typo pattern an edit-distance generator flags, typically a doubled-consonant error, a silent-letter drop, or a vowel substitution. It also participates in 1 confusable-pair relationship, "illnesses", a pairing that trips writers up because the two words share enough sound or shape to blur together.

Etymologically, the entry records: From ill + -ness. The correct English form is illness, spelled I-L-L-N-E-S-S.

Definition

  1. 1
    An instance of a disease or poor health.
  2. 2
    A state of bad health or disease.

Recorded use

Wiktionary examples

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

  1. Her grandmother had passed away after a long illness.
  2. suffer form a severe illness

Etymology

From ill + -ness.

Synonyms

sicknesssickness

This word in other languages

enfermedad(Español)maladie(Français)Krankheit(Deutsch)doença(Português)

Common misspellings

Also misspelled as:

  • illenss
  • illnes
  • illnness
  • illnses
  • ilness
  • ilnless
  • lilness

Misspelling Pattern Breakdown

How far each generated variant is from the correct spelling of illness - measured in single-character edits (insert, delete, or substitute a letter). Larger bars are easier to catch; one-edit slips are the sneakiest.

illenss2illnes1illnness1illnses2ilness1ilnless2lilness2
Edit distance from "illness"

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 "illness"?
"illness" is spelled I-L-L-N-E-S-S. The IPA pronunciation is /ˈɪl.nəs/.
What does "illness" mean?
As a noun, "illness" means: An instance of a disease or poor health.
What words are commonly confused with "illness"?
"illness" is commonly confused with "illnesses". These words look or sound similar but have different meanings. PlainSpell provides detailed comparisons for each pair.
How do you pronounce "illness"?
The IPA (International Phonetic Alphabet) transcription for "illness" is /ˈɪl.nəs/. 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 "illness"?
From ill + -ness. 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 "illness", not the corpus desk frequency band.

Same letter count

Frequency-ranked English headwords with 7 letters (nearest by frequency rank).

Mexican#3,571demands#3,553comfort#3,548colonel#3,547

Similar misspelling depth

Headwords with a similar count of attested misspellings (7 here; floor ≥5).

hired7 variantsfoods7 variantsknife7 variantsbureau7 variants

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

Source: FrequencyWords open word-frequency list