ill
adjective
ill
1 American
[il]
/ ɪl /
adjective
worse,
worst,
iller,
illest
-
of unsound physical or mental health; unwell; sick.
She felt ill, so her teacher sent her to the nurse.
-
objectionable; unsatisfactory; poor; faulty.
ill manners.
-
ill feeling.
-
of ill repute.
- Synonyms:
- iniquitous, wrong
- Antonyms:
- good
-
ill fortune.
-
of inferior worth or ability; unskillful; inexpert.
an ill example of scholarship.
-
His mom is the illest cook.
noun
-
ills
plural
-
an unfavorable opinion or statement.
I can speak no ill of her.
-
harm or injury.
His remarks did much ill.
- Synonyms:
- misery, affliction, pain, hurt
-
trouble, distress, or misfortune.
Many ills befell him.
- Synonyms:
- calamity
-
evil.
to know the difference between good and ill.
- Synonyms:
- depravity
-
sickness or disease.
- Synonyms:
- affliction, illness
adverb
-
in an ill manner.
-
unsatisfactorily; poorly.
It ill befits a man to betray old friends.
-
in a hostile or unfriendly manner.
-
unfavorably; unfortunately.
-
with displeasure or offense.
-
faultily; improperly.
-
with difficulty or inconvenience; scarcely.
Buying a new car is an expense we can ill afford.
idioms
I'll
2
American
[ahyl]
/ aɪl /
ill.
3
American
abbreviation
-
illustrated.
-
illustration.
-
illustrator.
-
most illustrious.
Ill.
4
American
abbreviation
ill
1
British
/ ɪl /
adjective
-
(usually postpositive) not in good health; sick
-
characterized by or intending evil, harm, etc; hostile
ill deeds
-
causing or resulting in pain, harm, adversity, etc
ill effects
-
ascribing or imputing evil to something referred to
ill repute
-
promising an unfavourable outcome; unpropitious
an ill omen
-
harsh; lacking kindness
ill will
-
not up to an acceptable standard; faulty
ill manners
-
unable to relax; uncomfortable
noun
-
evil or harm
to wish a person ill
-
a mild disease
-
misfortune; trouble
adverb
-
badly
the title ill befits him
-
with difficulty; hardly
he can ill afford the money
-
not rightly
she ill deserves such good fortune
Ill.
2
British
abbreviation
I'll
3
British
/ aɪl /
contraction
ill
More Idioms
Grammar
See well 1.
Usage
What are other ways to say ill? The adjective ill is defined as “evil; wicked; bad.” However, it’s not used in exactly the same way as any of those synonyms! Learn the difference among these terms on Thesaurus.com.
Synonym Usage
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.
Other Word Forms
Noun Inflected Forms
Etymology
Origin of ill1
1150–1200; Middle English ill ( e ) (noun and adj.) < Old Norse illr (adj.) ill, bad
Origin of ill.3
ill. ( def. 4 ) < Latin illustrissimus
Explanation
If you're ill, you're unwell, or sick. Being ill is a good excuse for missing work or school. You might get ill after being sneezed on by someone with a cold; or eating street food in a foreign country; or for no reason that you can point to. People can be mentally ill as well as physically ill, from depression or anxiety among other ailments. Ill can also mean "bad" in various ways, including when you suffer ill effects from going too long without sleep, or exercise ill judgment when you buy $500 worth of lottery tickets.
Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
See Examples For:
Disabled and terminally ill campaigners have written to Prime Minister Andy Burnham urging him to reform social and palliative care before assisted dying legislation is introduced in England and Wales.
From BBC ● Aug. 14, 2026
Workers are also falling ill younger and experiencing a more severe and rapid progression of the disease, according to an analysis of the state’s data published in the New England Journal of Medicine.
From Los Angeles Times ● Aug. 12, 2026
Another took responsibility for treating and feeding animals that had fallen ill.
From BBC ● Aug. 11, 2026
Despite a battery of tests, including a contrast CT scan and bone marrow biopsy, experts could not determine what was making Jackie critically ill.
From Los Angeles Times ● Aug. 10, 2026
She tried to imagine what it would be like to be ill and have no family.
From "Sadako and the Thousand Paper Cranes" by Eleanor Coerr
Nearly every line approaches platitude: “You can get lost in the blink of an eye”; “on a clear day you can see forever”; “I think one day I’ll slip away.”
From The Wall Street Journal ● Aug. 14, 2026
"This was money I'd invested to save before planning to leave my job around October to start my own business. But now I'm seriously wondering whether I'll have enough."
From BBC ● Aug. 13, 2026
If I’m ever down or need a little pick-me-up, I’ll literally just blast that soundtrack.
From Los Angeles Times ● Aug. 13, 2026
"I only hope that after I step down, people across the country will say that 'he was an honest official, not a corrupt one' and I'll be very satisfied with that," he said.
From Barron's ● Aug. 12, 2026
I’ve gone weeks without seeing anything, and sometimes, I’ll have one every other day.
From "Split the Sky" by Marie Arnold
"He was critically ill. His heart stopped as soon as he arrived. We had to perform CPR," said lead author Ankit Bharat, a thoracic surgeon at Northwestern University.
From Science Daily ● Mar. 18, 2026
"I am under so much stress that it's made me ill. My wife is also unwell. This is not human rights."
From BBC ● Mar. 18, 2026
"Tatler, you should be ashamed putting this on the cover. A child would have done a better job. I’m so angry you've done this whilst she is so ill. Shame on you."
From Salon ● May 23, 2024
“We have so appreciated all of the prayers and support from friends who knew he was very ill. Although it is hard for us to say goodbye, his peaceful passing was a blessing for him.”
From Los Angeles Times ● Apr. 16, 2024
One of them said “kent- land ill. 5.10.11.”
From "Bud, Not Buddy" by Christopher Paul Curtis
SPRINGFIELD, Ill. — For the last few years, Mo’ne Davis has enjoyed her anonymity.
From Los Angeles Times ● Aug. 2, 2026
Rivian currently builds its EVs at a plant in Normal, Ill., about three hours from Chicago.
From The Wall Street Journal ● Jul. 30, 2026
I was en route to the airport in Moline, Ill., nearly three decades ago.
From The Wall Street Journal ● Jul. 28, 2026
Ben Zwief, an adviser in Lake Forest, Ill., cites the example of a client with $50,000 in credit-card debt at a 20% interest rate.
From MarketWatch ● Jul. 2, 2026
I was born on March 9, 1943 in Chicago, Ill. U.S.A.
From "Endgame" by Frank Brady
What drives societal ills or ignites a social movement?
From The Wall Street Journal ● Jul. 25, 2026
As Dan Kois illustrates in this ode to kicking back with friends, spending unstructured time together is a blessedly simple cure to the ills of modern life.
From Slate ● Jul. 10, 2026
As Norway advance, is Wright correct about Scottish football's ills?
From BBC ● Jul. 7, 2026
In the video, Pratt stood outside Raman’s Silver Lake home and the city-owned Getty House in Hancock Park, where Bass lives, contending both are far removed from the urban ills that beset other Angelenos.
From Los Angeles Times ● May 21, 2026
In return he tried to make their lives comfortable, learning to cure their ills, treating their cuts and bruises as his mother treated his, combing burrs and prickles from their woolly coats.
From "Rowan of Rin" by Emily Rodda
"If you have a generally iller population, that's not good for the residents, it's not good for productivity, it's not good for the economy.'"
From BBC ● May 25, 2023
This gave him an unnatural appearance and made him look iller than ever.
From The New Yorker ● Dec. 30, 2019
He got iller and iller and iller, and of course he died in the beginning of 2015 when some of the other things had started appearing in the press.
From BBC ● Nov. 23, 2016
Still, in his older, iller years, he's become kinder, even to himself, and though he wished he'd done some stuff better, he could live with it.
From The Guardian ● Jun. 23, 2012
He's looking iller and older every day, and tells me himself that he never sees her now; it's too piteous to hear him, dear old thing.
From The War-Workers by E.M. Delafield
The Black neighborhoods like Baldwin Hills Estates, Ladera Heights and View Park all sit hillside with some of the illest views in the city.
From Los Angeles Times ● Apr. 13, 2026
His wife was told she should prepare for the worst, with staff describing her husband as "one of the illest people they'd ever seen".
From BBC ● May 21, 2024
Rapper Travis Scott told his nearly 12 million followers on X, the site formerly known as Twitter, that Monday “might be one for the illest days in women’s sports historyyyyyyy.”
From Seattle Times ● Apr. 2, 2024
Blaze is just one of the illest low heads.
From Salon ● Mar. 6, 2021
Not knowing is worse than the very illest news.
From Grey Town An Australian Story by Gerald Baldwin
He’s not the only disappointment: Mookie Betts is hitting worse than ever before in his career while another newcomer, $240-million man Kyle Tucker, is hitting just .239 with 11 home runs.
From Los Angeles Times ● Aug. 14, 2026
"Even though Europe's problems have only gotten worse with this summer's abnormally hot temperatures, drying rivers and further disrupting transport within the continent, earnings expectations for Stoxx 600 companies keep rising!"
From Barron's ● Aug. 14, 2026
"The more TBX5 you removed, the worse the disruption across every level of genome organization we looked at."
From Science Daily ● Aug. 13, 2026
Twenty bucks is a lot to pay for a piece of plastic you could lose to a strong fish, or worse, a rock.
From The Wall Street Journal ● Aug. 12, 2026
I followed Tansy into the schoolroom, which smelled worse.
From "The Teacher’s Funeral" by Richard Peck
Pereira's worst affected neighborhoods were also its most impoverished, with homeless people, Venezuelan migrants and street vendors in precarious situations bearing the brunt of the impact.
From Barron's ● Aug. 14, 2026
And, “Dr. Phil and Dr. Oz are the two worst things Oprah ever foisted on the public.”
From Los Angeles Times ● Aug. 14, 2026
It was the firm’s worst monthly loss ever, one of the people said.
From The Wall Street Journal ● Aug. 14, 2026
In contrast, Hal Jordan’s Green Lantern was immortalized on the big screen in 2011 by way of a laughable debacle that’s considered one of the worst career decisions Ryan Reynolds ever made.
From Salon ● Aug. 14, 2026
The worst part was seeing people with ugly whitish scars.
From "Sadako and the Thousand Paper Cranes" by Eleanor Coerr
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
