What does sick mean?
Sick is a common adjective meaning affected by illness or not in good health. People use it for temporary conditions, such as a fever or stomach complaint, and in phrases such as “sick with flu” or “get sick.” It can also form the highly useful expression “sick of,” meaning tired of or strongly opposed to something: a speaker may say they are sick of being interrupted. In informal English, especially American English, “sick” has additional meanings, including morally disgusting or exceptionally impressive. These extended senses depend on tone and are not appropriate for formal writing when discussing medical conditions. “Sick” is closely related to words such as sickness, sickly, sicken, and sickening, which reflect the same long-established Germanic root associated with illness and weakness.
Affected by an illness or lacking health; unwell. It can also mean tired of or irritated by something, or, informally, morally objectionable or very impressive.
"He was sick with a stomach virus and could not attend the meeting."
The informal meanings “disgusting” and “excellent” are context-dependent and should generally be avoided in formal writing.
A person who is ill, especially when used collectively for people who are unwell.
"The volunteers cared for the sick throughout the night."
The noun is now uncommon in general use and is more likely to appear in literary, historical, or collective contexts.
The word “sick” can mean physically unwell, fed up with something, morally disgusting, or—in informal praise—extremely impressive.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does sick come from?
The word descends from Old English sēoc, meaning ill or affected by disease. It belongs to the Germanic family and has relatives in modern German, Dutch, and other related languages. Over time, the same root developed into English forms such as sickness, sickly, and sicken, while modern idiomatic meanings such as “sick of” and the informal sense “excellent” are later developments.
Related word forms
How sick is actually used
In everyday English, “sick” is the usual word for being unwell. The phrase “sick of” is common in speech and writing, while “sick with” usually identifies an illness. “Sick” can be informal or colloquial when describing something as disgusting or excellent, and the latter sense is especially associated with American English.
Easily confused with sick
Sick describes a person or thing affected by illness, whereas sickly often emphasizes chronic weakness, poor health, or a tendency to become ill.
Ill and sick are broadly synonymous, but ill is somewhat more formal, while sick is more common in everyday speech.