sickness

noun

sick·​ness ˈsik-nəs 

1

a

: ill health : illness

b

: a disordered, weakened, or unsound condition

2

: a specific disease

3

: nausea, queasiness

Synonyms of sickness

• illness

Examples of sickness in a Sentence

He died from an unknown sickness.

she was plagued by sickness most of her adult life

Recent Examples on the Web

Agnes is both a seer and healer, preparing natural remedies for the townsfolk to help with ailments and sickness. —Nathan Smith, Time, 26 Nov. 2025

When these cats experienced changes in feeding schedule or caretaker, the healthy cats were just as likely to show sickness behaviors, such as refusing food, frequent vomiting and leaving waste outside the litter box, as the chronically ill cats. —Liz O'Connell, MSNBC Newsweek, 25 Nov. 2025

On June 9, Kennedy, a longtime skeptic of vaccine policies, dismissed all 17 members of the committee that advises the Centers for Disease Control and Prevention on vaccine recommendations for children and adults to prevent or lessen sickness and death. —Beth Warren, Nashville Tennessean, 22 Nov. 2025

But his son's sickness pushed Stephen Dickenson to a career change. —Bri Buckley, CBS News, 18 Nov. 2025

Word History

First Known Use

before the 12th century, in the meaning defined at sense 1a

Phrases Containing sickness

• acute mountain sickness
• African sleeping sickness
• altitude sickness
• decompression sickness
• milk sickness
• morning sickness
• motion sickness
• mountain sickness
• radiation sickness
• serum sickness
• sickness benefit
• sleeping sickness
• travel sickness

Rhymes for sickness

• quickness
• thickness
• homesickness
• seasickness

Kids Definition

sickness

noun

sick·​ness ˈsik-nəs 

1

: ill health : illness

2

: a specific disease : malady

3

: nausea sense 1

Medical Definition

sickness

noun

sick·​ness ˈsik-nəs 

1

: the condition of being ill : ill health

2

: a specific disease

3

: nausea