unhealthy

adjective

un·​healthy ˌən-ˈhel-thē 

unhealthier; unhealthiest

1

: not conducive to health : not healthful

an unhealthy climate

unhealthy habits

unhealthy foods

2

: not in good health : sickly, diseased

unhealthy animals

3

a

: risky, unsound

an unhealthy economy

b

: of a harmful nature : bad, injurious

unhealthy levels of lead

c

: morally contaminated : corrupt, unwholesome

an unhealthy imagination

unhealthily

ˌən-ˈhel-thə-lē 

adverb

unhealthiness

ˌən-ˈhel-thē-nəs 

noun

Synonyms

• insalubrious
• noisome
• noxious
• sickly
• unhealthful
• unwholesome

Examples of unhealthy in a Sentence

Her skin looks blotchy and unhealthy.

Tests revealed an unhealthy level of lead in the water.

Eating honey can be unhealthy for babies.

He was stuck in an unhealthy relationship.

She has an unhealthy interest in natural disasters.

Recent Examples on the Web

After more than a decade as a reviewer, Jason Bennett has an unhealthy love for rogue-lite survival games and terrible puns. —Jason Bennett, Arkansas Online, 29 June 2025

That means overcoming interpersonal tensions, freezing conditions, dwindling rations, and unhealthy CO2 levels, among other challenges, as well as taking on a pulse-pounding manual course correction with no navigational computer. —ArsTechnica, 29 June 2025

When air is stagnant, pollutants don't get dispersed, allowing ozone to build up to unhealthy levels. —Joe Edwards, MSNBC Newsweek, 27 June 2025

Eating mayonnaise on crackers feels flagrantly unhealthy, like smoking a cigarette outside the hospital. —Josh Miller, Southern Living, 27 June 2025

Word History

First Known Use

1595, in the meaning defined at sense 1

Rhymes for unhealthy

• healthy
• stealthy
• wealthy

Kids Definition

unhealthy

adjective

un·​healthy ˌən-ˈhel-thē 

1

: not conducive to good health : not healthful

an unhealthy climate

2

: not in good health : sickly, diseased

3

a

: risky, unsound

an unhealthy economy

b

: injurious, bad

unhealthily

-thə-lē 

adverb

unhealthiness

-thē-nəs 

noun

Medical Definition

unhealthy

adjective

un·​healthy -ˈhel-thē 

unhealthier; unhealthiest

1

: not conducive to health

an unhealthy climate

2

: not in good health : sickly

unhealthiness noun