illness

noun

ill·​ness ˈil-nəs 

1

a

: sickness sense 2

b

: an unhealthy condition of body or mind

2

obsolete

a

: wickedness

b

: unpleasantness

Synonyms of illness

• disease
• ailment
• ill
• sickness
• fever

Examples of illness in a Sentence

Her body was not able to defend itself against illness.

Hundreds of soldiers died from illness and hunger.

He showed no signs of illness.

Scientists have not yet found a cure for this illness.

cancer, diabetes, and other illnesses

She died at the age of 60 after a brief illness.

Recent Examples on the Web

The camp was rife with illnesses, including cholera, and Ibrahim became severely sick. —Annie Hylton, New Yorker, 14 May 2026

Hantavirus is typically spread through contact with infected rodents and can lead to severe respiratory illness, though cases remain rare, according to the WHO. —Brittany Miller, FOXNews.com, 14 May 2026

According to a source briefed on the situation, the illness was contained to the Victoire. —Hailey Salvian, New York Times, 13 May 2026

The report describes widespread neurological illness, chronic disease and collapsing food systems in mining zones where rivers can no longer safely provide fish or drinking water. —Antonio María Delgado, Miami Herald, 13 May 2026

Word History

First Known Use

circa 1500, in the meaning defined at sense 2a

Phrases Containing illness

• bipolar illness
• illness anxiety disorder
• manic-depressive illness
• mental illness

Rhymes for illness

• stillness

Kids Definition

illness

noun

ill·​ness ˈil-nəs 

1

: an unhealthy condition of body or mind

2

: sickness sense 2

Medical Definition

illness

noun

ill·​ness ˈil-nəs 

: an unhealthy condition of body or mind : sickness