ill

/ɪl/

//ɪl// adj

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

"ill" is a 3-letter English headword indexed on PlainSpell.

The verdict

“ill” sits in 20 confusable pairs (corpus #1,946) as an adjective. The look-alike neighbours are the real trap.

#1,946
frequency rank, English
2,140
“I” headwords
20
confusable pairs

According to Wiktionary data (CC BY-SA, analyzed September 3, 2026) - Evil; wicked (of people).

Corpus desk

Index EN-ill · ill · English

ill · rank #1,946 · 0 variants · 20 confusables

  • FREQ-COMMON #1,946
  • LEN-MID 3 letters
  • VOW-1 1 vowel
  • CONFUS-HIGH 20 pairs
  • VAR-0 0 variants
  • BOOK-MID 2,140
  • PHOTO-FINISH houses

Nearest frequency peer: houses (-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.

Frequency neighbours of confusable “ill”

Peers at similar corpus weight, separate from look-alike pairs below

corpus weight

What this shows Bars place “ill” against nearest ranked English headwords, not a reprint of the confusable-pair desk.

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).

ill vs in
33% similar
ill vs is
33% similar
ill vs it
33% similar

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

Key facts for ill
PropertyValue
Headwordill
LanguageEnglish
Part of speechAdjective
IPA/ɪl/
Letters3
Frequency rank#1,946
Misspellings tracked0
Confusable pairs20
SourceWiktionary (kaikki.org)

Corpus rank beside confusables of “ill”

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).illlands here:

#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. Same rarity band neighbours include “houses” (#1,945), “initial” (#1,947), “hello” (#1,944). Among 2,140 “I” headwords, “ill” is #1,946. Source: FrequencyWords open word-frequency list.

Easy to mix with look-alikes

The spelling risk for ill is neighbouring look-alikes ("in", "is", …), not just typos; it is anadjective pronounced /ɪl/. Frequency #1,946 among 2,140 “I” headwords. 10 recorded senses keep meaning in play.

ill doesn't appear in our generated misspelling index, since its letter sequence doesn't invite the usual edit-distance slips. It also participates in 20 confusable-pair relationships, "in", "is", "it", and more, a pairing that trips writers up because the two words share enough sound or shape to blur together.

Etymologically, the entry records: From Middle English ille (“evil; wicked”), from Old Norse íllr (adjective), ílla (adverb), ílt (noun), from Proto-Germanic *ilhilaz, from Proto-Indo-European *h₁elḱ- (whence Latin ulcus (“sore”), Ancient Greek ἕλκος (hélkos, “wound, ulcer”), Sanskrit अर्शस्… The correct English form is ill, spelled I-L-L.

Definition

  1. 1
    Evil; wicked (of people).
  2. 2
    Morally reprehensible (of behaviour etc.); blameworthy.
  3. 3
    Indicative of unkind or malevolent intentions; harsh, cruel.
  4. 4
    Unpropitious, unkind, faulty, not up to reasonable standard.
  5. 5
    Unwell in terms of health or physical condition; sick.
  6. 6
    Nauseated; having an urge to vomit.
  7. 7
    Sublime, with the connotation of being so in a singularly creative way.
  8. 8
    Extremely bad (bad enough to make one ill). Generally used indirectly with to be.
  9. 9
    Unwise; not a good idea.
  10. 10
    Bad-tempered.

Recorded use

Wiktionary examples

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

  1. St. Paul chose to magnify his office when ill men conspired to lessen it.
  2. A man who is conscious of having an ill character, cannot justly be angry with those who neglect and slight him.

Etymology

From Middle English ille (“evil; wicked”), from Old Norse íllr (adjective), ílla (adverb), ílt (noun), from Proto-Germanic *ilhilaz, from Proto-Indo-European *h₁elḱ- (whence Latin ulcus (“sore”), Ancient Greek ἕλκος (hélkos, “wound, ulcer”), Sanskrit अर्शस् (árśas, “hemorrhoids”)). Cognates Cognate with Scots and Yola ill, Danish ilde (“bad”), Faroese, Icelandic illur (“bad, ill, wicked”), Norwegian Bokmål, Norwegian Nynorsk ille (“bad”), Swedish illa (“badly; poorly”).

Synonyms

diseasedpoorlysickunder the weatherunwellailingdisgustednauseatednauseoussicksickenbadmal-dopecrankcrookgreen about the gillsickyillindisposedinfirmlike death warmed overmaladivemawkishoff one's feedon the Pat and Mickout of sortsPat and Mickqueersickishsicklysick as a dogsick as a parrotunhealthyvaletudinarianvaletudinary

Antonyms

finehalehealthyin good healthwellgoodwack

This word in other languages

enfermo(Español)malade(Français)krank(Deutsch)doente(Português)

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 "ill"?
"ill" is spelled I-L-L. The IPA pronunciation is /ɪl/.
What does "ill" mean?
As an adjective, "ill" means: Evil; wicked (of people).
What words are commonly confused with "ill"?
"ill" is commonly confused with "in", "is", "it". These words look or sound similar but have different meanings. PlainSpell provides detailed comparisons for each pair.
How do you pronounce "ill"?
The IPA (International Phonetic Alphabet) transcription for "ill" is /ɪl/. 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 "ill"?
From Middle English ille (“evil; wicked”), from Old Norse íllr (adjective), ílla (adverb), ílt (noun), from Proto-Germanic *ilhilaz, from Proto-Indo-European *h₁elḱ- (whence Latin ulcus (“sore”), Ancient Greek ἕλκος (hélkos, “wound, ulcer”), Sansk... 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 "ill", not the corpus desk frequency band.

Same letter count

Frequency-ranked English headwords with 3 letters (nearest by frequency rank).

tea#1,925sky#1,968lee#1,905bay#1,889

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

Source: FrequencyWords open word-frequency list