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

Wash used blankets immediately after sickness to avoid passing viruses and germs between household members. —Emily Benda Gaylord, The Spruce, 2 Jan. 2026

Health officials say a new version of influenza A is driving the spike in sickness across Texas and the rest of the country right now. —Tiffani Jackson, Fort Worth Star-Telegram, 31 Dec. 2025

Additionally, food particles tend to remain in the dishwasher from cycle to cycle, which could cause sickness or allergic reactions due to cross-contamination, Brigman warns. —Madeline Buiano, Martha Stewart, 30 Dec. 2025

Likewise, signals of internal sickness teach the brain to anticipate illnesses that have yet to start. —The New York Times News Service Syndicate, San Diego Union-Tribune, 30 Dec. 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