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

• affection
• ail
• ailment
• bug
• complaint
• complication
• condition
• disease
• disorder
• distemper
• distemperature
• fever
• ill
• infirmity
• malady
• sickness
• trouble

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

Mahler died in 1911 from illnesses exacerbated by a heart condition, at just 50. —Hannah Edgar, Chicago Tribune, 14 Apr. 2025

Tocchet also announced Sunday that goaltender Thatcher Demko would be shut down for the season due to illness, which necessitated an emergency call-up of Nikita Tolopilo on Saturday. —Thomas Drance, New York Times, 14 Apr. 2025

Death may force the succession of leadership, but so might incapacitation due to injury or illness, a desire to pursue other interests or even a spouse insisting on a move to a warmer climate. —Gerry Spitzer, Forbes.com, 14 Apr. 2025

During its workshops, outdoor workers learn what heat illness is and its symptoms as well as how to help co-workers suffering from extreme heat. —Mimi Whitefield, Miami Herald, 14 Apr. 2025

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