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

Kind of like with any sickness, getting to the root of the problem with a medical professional will do more than downing a multitude of hot beverages. —Sara Kiley Watson, Popular Science, 26 Feb. 2026

In addition to bird flu concerns among commercial and backyard flocks, the Pennsylvania Game Commission is asking the public to be on alert for sickness in wild birds as migration ramps up in the coming weeks. —Alexandra Simon, CBS News, 24 Feb. 2026

This can also help keep sickness at bay, as a healthier gut microbiome is linked to better immune function, according to Wright. —Kirsten Nunez, Martha Stewart, 20 Feb. 2026

On top of the sickness running through the team, the Huskies are also managing a slew of minor injuries. —Emily Adams, Hartford Courant, 19 Feb. 2026

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