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 true sickness is the conditions that so many infants endure through no fault of their own, which lead to these outcomes. — Ronald J. Allen, Chicago Tribune, 19 July 2026

And while children, the elderly and those with certain sicknesses or medications are most susceptible to heat illness – these temperatures affect everyone. — Ashley Miznazi, Miami Herald, 17 July 2026

In other words, that pain of sickness, that fever, is what’s killing the virus within you. — Kevin Kruse, Forbes.com, 17 July 2026

In a clip from the show, granddaughter Kim Kardashian detailed that her grandmother had survived colon cancer and breast cancer and, in her sunset years, struggled with sickness resulting from the cancer treatments. — Emily St. Martin, Los Angeles Times, 16 July 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