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:
“When she got ill ... she got out of her bed to sing this song. And you can hear that,” Bono told Rolling Stone.
From Los Angeles Times ● Sep. 25, 2026
My closest friend of more than 40 years is terminally ill, with most likely less than a year to live.
From MarketWatch ● Sep. 25, 2026
In addition to worrying about his ill daughter, Bach mutters and growls about the Prussian troops rampaging through his town.
From The Wall Street Journal ● Sep. 24, 2026
Mackintosh said pressures placed on young people who are working and studying, in particular, can lead to them taking as much over the counter to "keep going when they're ill".
From BBC ● Sep. 22, 2026
In 1794, Washington had sent Chief Justice John Jay to London to negotiate a realistic bargain that avoided a war with England at a time when the United States was ill prepared to fight one.
From "Founding Brothers: The Revolutionary Generation" by Joseph J. Ellis
Some soups depend on freshness, delicacy or a particularly clean broth, and I’ll get to those.
From Salon ● Sep. 28, 2026
I’ll call Burgum and tell him it’s allowable in Nevada’—that’s as simple as it was.”
From The Wall Street Journal ● Sep. 27, 2026
"If someone calls me an influencer I'll take it as a compliment. Because the real influence I can have is to make people think for themselves."
From BBC ● Sep. 26, 2026
I’ll make me a big cup of tea.
From Los Angeles Times ● Sep. 25, 2026
I go to my room in the hope I’ll find something to do so that I am not locked in with my thoughts.
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
"All of these people have had hepatitis C for more than three decades; some are very ill. A more proactive approach is critical to reaching and diagnosing those who remain unaware of their infection."
From BBC ● May 18, 2025
“I walked into the facility healthy and feeling fine, and within 24 hours I became severely ill. I had severe burning in my face, tremors, twitching; I felt like I was being electrocuted.”
From Los Angeles Times ● Mar. 12, 2025
Another shares: "When I see someone making really small repetitive movements, such as my husband bending his toes, I feel physically ill. I hold it back but I want to vomit."
From BBC ● Dec. 12, 2024
“Beowulf is also ill. He claims to have a headache in his leg.”
From "The Interrupted Tale" by Maryrose Wood
His family moved to Decatur, Ill., where Archer-Daniels-Midland was based, after the agricultural giant named him to its board in 1991.
From The Wall Street Journal ● Sep. 19, 2026
The company expects eventually to increase annual production capacity at its plant in Normal, Ill., to 215,000 vehicles, adding potentially another 300,000 in capacity through its plant in Stanton Springs, Ga.
From MarketWatch ● Sep. 17, 2026
The Vittitoes were paying more than $13,000 a year on their home in Washington, Ill., outside Peoria.
From The Wall Street Journal ● Sep. 13, 2026
SPRINGFIELD, Ill. — Isabella Villareal practiced with the Los Angeles Queens for the first time on Saturday morning, hours before the team’s first game.
From Los Angeles Times ● Aug. 2, 2026
I was born on March 9, 1943 in Chicago, Ill. U.S.A.
From "Endgame" by Frank Brady
Time, perhaps, to question whether he's got the answers to the myriad ills of his team.
From BBC ● Sep. 20, 2026
They fear the uncertainties of artificial intelligence and suffer the ills of inflation.
From The Wall Street Journal ● Jul. 29, 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 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
Last year began with my being ill, kept on with my being iller, then I was unwell, followed by being poorly with a tiny interlude of infirmity.
From The Guardian ● Aug. 15, 2012
This, in turn, was the very thing to keep him but ill at ease with himself, and iller at ease, if not at downright loggerheads, with everybody else.
From The Red Moccasins A Story by Morrison Heady
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
It’s one of the illest, if not the illest Caribbean food spots in the city.
From Washington Post ● Aug. 22, 2022
Not knowing is worse than the very illest news.
From Grey Town An Australian Story by Gerald Baldwin
Or, worse, calling the board’s chair to complain about their replacement?
From The Wall Street Journal ● Sep. 29, 2026
You have identified a problem that will probably only get worse as you age and you face more challenges with mobility.
From MarketWatch ● Sep. 29, 2026
Irvine said the issue had been even worse during this summer's heatwaves, which had led to her being prescribed medication for migraines.
From BBC ● Sep. 28, 2026
Those disturbances have been linked with worse recovery, depression, and reduced quality of life.
From Science Daily ● Sep. 28, 2026
And, worse than that, I’ve upset Bubbe and pushed her even further away.
From "Code Name Kingfisher" by Liz Kessler
But, despite its upgrade for Zandvoort, the Honda engine remains the worst on the grid, in terms of overall power, driveability and energy management.
From BBC ● Sep. 29, 2026
After another rough week, the bond market’s no-good September continued on Monday, with the Treasury market on the verge of booking one of its worst monthly showings in years.
From MarketWatch ● Sep. 28, 2026
The bond selloff of 2022 was by some measures the worst in U.S. history.
From The Wall Street Journal ● Sep. 27, 2026
When a clown’s only trick is shouting into a live microphone, the absolute worst thing that can happen is for the cameras to simply turn off.
From Salon ● Sep. 27, 2026
“Do you think—?” Glory let herself think the worst.
From "The Way to Rio Luna" by Zoraida Cordova
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.
