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

Some, Mute said, suggested that the spreading sickness was tuberculosis, AIDS or even mercury poisoning — from the chemical that miners use to extract gold from ore. — Emmet Livingstone, NPR, 24 June 2026

Around the same time, Martinez said, fire rescue received a few medical calls from fans experiencing heat sickness at the event. — Ashley Miznazi, Miami Herald, 23 June 2026

Instead of letting a bad packing habit risk sickness, stay healthy by making a few small tweaks to your travel routine, starting with snagging a shoe bag for under $20. — Olivia Young, Travel + Leisure, 22 June 2026

Though minor gastrointestinal discomfort is the most common symptom of exposure, pathogens that may cause only minor sickness in some people may cause serious conditions or death in the very young, old, or those with weakened immune systems. — Christopher Edwards, PEOPLE, 19 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