unsustainable

adjective

un·​sus·​tain·​able ˌən-sə-ˈstā-nə-bəl 

: not capable of being prolonged or continued : not sustainable

unsustainable agricultural practices

unsustainable growth

unsustainability

ˌən-sə-ˌstā-nə-ˈbi-lə-tē 

noun

unsustainably

ˌən-sə-ˈstā-nə-blē 

adverb

an unsustainably high rate of growth

Examples of unsustainable in a Sentence

Recent Examples on the Web

Traffic in the Strait of Hormuz has largely rebounded, but only at great risk to tankers, 20 of which have been struck in the last month, suggesting recovery could be unsustainable. — Morgan Chalfant, semafor.com, 7 Oct. 2026

But the constant challenge of trying to unite Fox Sports’ more traditional show with Barstool’s persona proved unsustainable. — Andrew Marchand, New York Times, 3 Oct. 2026

When deficits and the debt-to-GDP ratio reach unsustainable highs, bond buyers conclude that the government’s current policies are not credible and must change. — Steve H. Hanke, Fortune, 2 Oct. 2026

Debt concerns have also weighed on the bond market, as massive government spending from both political parties is putting the country on an unsustainable fiscal path. — David Goldman, CNN Money, 1 Oct. 2026

Word History

First Known Use

circa 1677, in the meaning defined above

Rhymes for unsustainable

• attainable
• explainable
• maintainable
• obtainable
• sustainable
• ascertainable
• unattainable
• unexplainable
• unobtainable
• trainable