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Definitions

unhealthy

[uhn-hel-thee] / ʌnˈhɛl θi /
ADJECTIVE
sick
Synonyms
STRONGEST
delicate unsound
WEAK
ailing below par debilitated diseased down dragging feeble frail ill in a decline in ill health in poor health infirm invalid laid low out of action out of shape peaked poorly run down shaky sickly unwell weak
Antonyms
STRONGEST
strong
WEAK
good healthy well
ADJECTIVE
very bad in effect on well-being
Synonyms
STRONGEST
corrupt corrupting dangerous degrading detrimental harmful hazardous negative noxious perilous perverse poisonous risky undesirable unsanitary unsound
WEAK
baneful chancy degenerate deleterious demoralizing insalubrious jeopardous morbid nefarious noisome rotten treacherous unhealthful unwholesome villainous virulent wicked
Antonyms
STRONGEST
certain good guarded helpful pure safe secure sound wholesome
WEAK
healthy strong well

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

At its peak, smoke from the underground fire was affecting air quality across Metro Manila, where an "acutely unhealthy" reading was recorded in multiple areas, according to a local monitor.

From Barron's • Apr. 30, 2026

A 2025 internal document spotlighted YouTube’s “two biggest challenges” for teen well-being: low-quality recommendations that can “normalize unhealthy beliefs” and “prolonged unintentional use.”

From The Wall Street Journal • Apr. 29, 2026

Once again this season was finding new, and exhilarating ways, of getting the pulse beating at an unhealthy rate.

From BBC • Apr. 26, 2026

San Bernardino County ranked as the most ozone-polluted county in the nation, with 159.2 weighted average unhealthy ozone days, followed by Riverside County at 126.7 and Los Angeles County at 119.0.

From Los Angeles Times • Apr. 22, 2026

Now, he couldn’t help thinking that Octavian looked like a watered-down, unhealthy version of Will Solace - like a photo that had been copied too many times.

From "Blood of Olympus" by Rick Riordan