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

This unsustainable mismatch must come into balance, one way or another. — Matt Egan, CNN Money, 13 Aug. 2026

That's because forgiveness programs are often reserved for those with larger, unsustainable amounts, with $7,500 often being the starting point. — Matt Richardson, CBS News, 12 Aug. 2026

Summary The retail trading industry is undergoing a quiet reckoning, as its decade-long focus on maximizing activity like sign-ups and trades proves unsustainable. — Daniel Schlaepfer, Forbes.com, 12 Aug. 2026

The sheer volume of summer crowds has become so unsustainable that the mayor, Sylvie Siri, is now publicly pleading with travelers to visit during the off-season instead, according to the BBC. — Andrea Margolis, FOXNews.com, 12 Aug. 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