unhealthful

adjective

un·​health·​ful ˌən-ˈhelth-fəl 

also -ˈheltth-

: harmful to health of body or mind : unhealthy sense 1

unhealthful levels of water pollution

an unhealthful diet

an unhealthful tendency to worry

Synonyms of unhealthful

• poisonous
• toxic
• unhealthy
• unwholesome
• noxious
• insalubrious
• sickly

Examples of unhealthful in a Sentence

the unhealthful level of smog in the city

Recent Examples on the Web

Warnings of unhealthful air quality remained in effect Saturday across a wide swath of the United States due to smoke from Canadian wildfires that has engulfed the Northeast in haze for days. — Los Angeles Times, 18 July 2026

The soil may contain pathogens, pesticides and other unhealthful things. — Joan Morris, Mercury News, 9 Feb. 2026

The unhealthful effects of autocracy remain robust even when accounting for economic differences and when excluding Venezuela and its collapsing health-care system. — Thomas J. Bollyky, Foreign Affairs, 30 Jan. 2020

Word History

First Known Use

1580, in the meaning defined above

Rhymes for unhealthful

• healthful

Kids Definition

unhealthful

adjective

un·​health·​ful

ˌən-ˈhelth-fəl

: unhealthy sense 1

Medical Definition

unhealthful

adjective

un·​health·​ful -ˈhelth-fəl 

: detrimental to good health

unhealthful working conditions

unhealthfulness noun