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

The other thing that was really interesting is this weeping sickness that Sugi described in the beginning. —Fiction Non Fiction, Literary Hub, 11 June 2026

Kelly Turner, a professor of urban planning at UCLA, stressed that heat sickness tracks closely with social inequality and is preventable. —Blanca Begert, Los Angeles Times, 4 June 2026

The crew also supported a variety of scientific experiments, including a study on the social behavior of ants without gravity, how metal alloys form in microgravity, and even a study on space sickness. —Chelsea Gohd, Space.com, 3 June 2026

Foodborne sickness prevention and treatment is uneven globally, and low- and middle-income countries are especially at risk for deaths and severe infections, Jean said. —Madeline Holcombe, CNN Money, 3 June 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