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

According to the governor’s office, people who are overweight may be prone to heat sickness because of their tendency to retain more body heat. — Justin Muszynski, Hartford Courant, 29 June 2026

Instead, God gives us authority over sin and sickness. — Lisa Rennie Sytsma, Christian Science Monitor, 26 June 2026

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

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