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 eating habits

unhealthy levels of lead

c

: involving or causing feelings or thoughts that are not normal and healthy

an unhealthy relationship

has an unhealthy interest in natural disasters

unhealthily

ˌən-ˈhel-thə-lē 

adverb

unhealthiness

ˌən-ˈhel-thē-nəs 

noun

Synonyms of unhealthy

• poisonous
• toxic
• unhealthful
• unwholesome
• sickly
• noxious

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

The agency advises limiting outdoor activities during unhealthy air days. —Forum News Service, Twin Cities, 8 May 2026

Whether at the grocery store, or driving past a fast-food restaurant, she's less tempted to buy an extra or unhealthy snack. —Betty Lin-Fisher, USA Today, 8 May 2026

Critics have said that Brandy Melville’s clothing, which typically fit an American extra small or small, encourages unhealthy body standards, especially among teenage girls. —Carolyn Stein, Chicago Tribune, 8 May 2026

In unhealthy relationships, money can be used as a tool of control in many different ways. —Joy Harden Bradford, AJC.com, 7 May 2026

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