ill

UK: /ˈɪl/ US: /ɪl/ ,(il)

Inflections of 'ill' (adv):

worse

adv comparative

worst

adv comparative

Inflections of 'ill' (adj):

worse

adj comparative

worst

adj superlative

WordReference Random House Learner's Dictionary of American English © 2025

ill /ɪl/   adj., worse/wɜrs/  worst /wɜrst/   n., adv. 

adj. 

1. Pathology sick;
   unwell;
   of poor health:
   [be + ~] She's ill and won't be in today.
2. hostile;
   unkind:
   [before a noun] ill feeling.
3. evil;
   wicked:
   [before a noun] ill deeds.
4. unfavorable:
   [before a noun] ill fortune.

n. 

5. an unfavorable opinion or statement:
   [uncountable] I can speak no ill of her.
6. harm or injury:
   [uncountable] His remarks did much ill.
7. trouble;
   misfortune:
   [countable] Many ills befell him.

adv. 

8. unsatisfactorily;
   poorly;
   badly:
   It ill befits a person to betray friends.
9. faultily;
   improperly:
   an ill-constructed house.
10. with difficulty or inconvenience:
    an expense we can ill afford.
11. The word ill can be used in combination with other adjectives or participles to mean "badly, improperly;
    inadequately:''
    ill- + considered → ill-considered (= not thought out well in advance;
    inappropriate);
    ill- + defined → ill-defined (= not well defined or clearly set out).

Idioms

12. Idioms ill at ease, uncomfortable;
    uneasy:
    When I first arrived at the party I felt very ill at ease because I didn't know anyone.
13. speak ill of, [~ + object] to say unfriendly or unpleasant things about:
    unwise to speak ill of the dead.

Related Words

ill is an adjective, illness is a noun: He was feeling ill. He had a strange illness.

I'll /aɪl/  

1. Pronouns contraction of I will;
   I shall.

Ill.,  an abbreviation of:

1. Place Names Illinois.

ill.,  an abbreviation of:

1. illustrated.
2. illustration.
3. illustrator.

WordReference Random House Unabridged Dictionary of American English © 2025

ill  (il), adj., worse, worst, n., adv. 
adj. 

1. Pathology of unsound physical or mental health;
   unwell;
   sick:
   She felt ill, so her teacher sent her to the nurse.
2. objectionable;
   unsatisfactory;
   poor;
   faulty:
   ill manners.
3. hostile;
   unkindly:
   ill feeling.
4. evil;
   wicked;
   bad:
   of ill repute.
5. unfavorable;
   adverse:
   ill fortune.
6. of inferior worth or ability;
   unskillful;
   inexpert:
   an ill example of scholarship.
7. Idioms ill at ease, socially uncomfortable;
   nervous:
   They were ill at ease because they didn't speak the language.

n. 

8. an unfavorable opinion or statement:
   I can speak no ill of her.
9. harm or injury:
   His remarks did much ill.
10. trouble, distress, or misfortune:
    Many ills befell him.
11. evil:
    to know the difference between good and ill.
12. Pathology sickness or disease.

adv. 

13. in an ill manner.
14. unsatisfactorily;
    poorly:
    It ill befits a man to betray old friends.
15. in a hostile or unfriendly manner.
16. unfavorably;
    unfortunately.
17. with displeasure or offense.
18. faultily;
    improperly.
19. with difficulty or inconvenience;
    scarcely:
    Buying a new car is an expense we can ill afford.

• Old Norse illr (adjective, adjectival) ill, bad
• Middle English ill(e) (noun, nominal and adjective, adjectival) 1150–1200

Synonyms

• 1. unhealthy, ailing, diseased, afflicted.
  Ill, sick mean being in bad health, not being well.
  Ill is the more formal word. In the U.S. the two words are used practically interchangeably except that sick is always used when the word modifies the following noun:
  He looks sick
  (ill); a sick person. In England,
  sick is not interchangeable with ill, but usually has the connotation of nauseous:
  She got sick and threw up.
  sick, however, is used before nouns just as in the U.S.:
  a sick man.
• 4. wrong, iniquitous. See bad ¹.
• 9. hurt, pain, affliction, misery.
• 10. calamity.
• 11. depravity.
• 12. illness, affliction.
• 14. badly.

Antonyms

• 1. well, healthy.
• 4. good.

I'll  (īl), 

1. Pronouns contraction of I will.

Usage

See contraction. 

Ill., 

1. Place Names Illinois.

ill., 

1. illustrated.
2. illustration.
3. illustrator.
4. most illustrious.
• Latin illustrissimus
• (def. 4)

Collins Concise English Dictionary © HarperCollins Publishers::

ill / ɪl/ adjective (worse, worst)

1. (usually postpositive) not in good health; sick
2. characterized by or intending evil, harm, etc; hostile: ill deeds
3. causing or resulting in pain, harm, adversity, etc
4. ascribing or imputing evil to something referred to: ill repute
5. promising an unfavourable outcome; unpropitious: an ill omen
6. harsh; lacking kindness: ill will
7. not up to an acceptable standard; faulty: ill manners
8. ill at ease ⇒ unable to relax; uncomfortable

noun

1. evil or harm
2. a mild disease
3. misfortune; trouble

adverb

1. badly: the title ill befits him
2. with difficulty; hardly: he can ill afford the money
3. not rightly: she ill deserves such good fortune

Etymology: 11th Century (in the sense: evil): from Old Norse illr bad

WordReference Random House Learner's Dictionary of American English © 2025

worse /wɜrs/   adj., comparative of  bad and ill.

1. bad or ill to a greater extent;
   inferior:
   Your score is worse on this test than on yesterday's.
2. more unfavorable or injurious.
3. in poorer health:
   The patient is worse than yesterday.

n. [uncountable* usually: the + ~]

4. something that is worse:
   a turn for the worse.

adv. 

5. in a worse manner:
   The class behaved worse than ever just when the principal came in.
6. to a worse degree:
   I feel much worse than yesterday.

WordReference Random House Learner's Dictionary of American English © 2025

worst /wɜrst/   adj., superlative of bad and ill.

1. bad or ill in the most extreme degree;
   most faulty or unsatisfactory:
   the worst job I've ever seen.
2. most unpleasant, unattractive, or disagreeable.
3. least efficient or skilled:
   The worst drivers in the country come from that state.

n. [uncountable* usually: the + ~]

4. something that is worst:
   Prepare for the worst.

adv. 

5. in the worst manner.
6. in the greatest degree.

v. [~ + object]

7. to defeat;
   beat.

Idioms

8. Idioms at (the) worst, under the worst conditions.
9. Idioms if worst comes to worst, if the very worst happens.
10. Idioms in the worst way, very much;
    extremely:
    He needs praise in the worst way.

WordReference Random House Unabridged Dictionary of American English © 2025

worse  (wûrs), adj., [comparative of] bad [and] ill. 

1. bad or ill in a greater or higher degree;
   inferior in excellence, quality, or character.
2. more unfavorable or injurious.
3. in less good condition;
   in poorer health.

n. 

4. that which is worse.

adv. 

5. in a more evil, wicked, severe, or disadvantageous manner.
6. with more severity, intensity, etc.;
   in a greater degree.

• bef. 900; Middle English (adjective, adjectival, adverb, adverbial, and noun, nominal); Old English wiersa (comparative adjective, adjectival), wiers (adverb, adverbial); cognate with Old Norse verri, Gothic wairsiza; see war²

WordReference Random House Unabridged Dictionary of American English © 2025

worst  (wûrst), adj., [superlative of] bad [and] ill. 

1. bad or ill in the highest, greatest, or most extreme degree:
   the worst person.
2. most faulty, unsatisfactory, or objectionable:
   the worst paper submitted.
3. most unfavorable or injurious.
4. in the poorest condition:
   the worst house on the block.
5. most unpleasant, unattractive, or disagreeable:
   the worst personality I've ever known.
6. most lacking in skill;
   least skilled:
   the worst typist in the group.
7. Informal Terms in the worst way, in an extreme degree;
   very much:
   She wanted a new robe for Christmas in the worst way.
   Also, the worst way. 

n. 

8. that which is worst.
9. at worst, if the worst happens;
   under the worst conditions:
   He will be expelled from school, at worst.
   Also, at the worst. 
10. get the worst of something, to be defeated by;
    lose:
    to get the worst of a fight.
11. if worst comes to worst, if the very worst happens:
    If worst comes to worst, we still have some money in reserve.

adv. 

12. in the most evil, wicked, severe, or disadvantageous manner.
13. with the most severity, intensity, etc.;
    in the greatest degree.

v.t. 

14. to defeat;
    beat:
    He worsted him easily.

• bef. 900; Middle English worste (adjective, adjectival, adverb, adverbial, and noun, nominal), Old English wur(re)sta, wyr(re)st, wer(re)sta (adjective, adjectival and adverb, adverbial); cognate with Old Norse verstr; see worse, -est¹

Collins Concise English Dictionary © HarperCollins Publishers::

I'll / aɪl/ contraction

1. I will or I shall

Collins Concise English Dictionary © HarperCollins Publishers::

Ill. abbreviation

1. Illinois