illness
Americannoun
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poor health; sickness.
He grew up in an environment known for poverty, illness, and little opportunity for education.
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a specific sickness or disease, or an instance of such.
Please be as accurate as possible in listing your childhood illnesses.
- Synonyms:
- infirmity, affliction, ailment
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Obsolete. wickedness.
noun
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a disease or indisposition; sickness
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a state of ill health
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obsolete wickedness
Usage
What does illness mean? Illness is a state of poor health or sickness, as in I’ve had to miss a lot of work due to illness. The word illness is also commonly used to refer to a disease or instance of sickness. This sense of the word is often used when the type of disease is uncertain or unknown or when someone doesn’t want to specify what it is, as in They said that he is in the hospital with an illness, but they didn’t provide any further details. The word illness is based on the adjective ill, meaning sick. Example: The best way to avoid illness is to thoroughly wash your hands.
Etymology
Origin of illness
Compare meaning
How does illness compare to similar and commonly confused words? Explore the most common comparisons:
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.
Illness is predicted to spread faster, infect more people and put higher-risk groups at greater chance of being seriously ill or hospitalized.
From Salon • Nov. 28, 2025
Illness doesn’t reflect a lack of effort, and bad things happen to the most proactive among us.
From The Wall Street Journal • Oct. 27, 2025
It would likely be useful for the more than 40 million adults in the U.S, who, according to the National Alliance on Mental Illness, suffer from an anxiety disorder.
From Los Angeles Times • Nov. 27, 2024
Brian Dow, deputy chief executive of the mental health charity Rethink Mental Illness, believes the state of mental healthcare in the UK has made tragic outcomes inevitable.
From BBC • Aug. 12, 2024
Illness and death still exist and cannot be hidden.
From "The Lives of a Cell" by Lewis Thomas
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.
