unsustainable

adjective

un·​sus·​tain·​able ˌən-sə-ˈstā-nə-bəl How to pronounce unsustainable (audio)
Synonyms of unsustainablenext
: not capable of being prolonged or continued : not sustainable
unsustainable agricultural practices
unsustainable growth
unsustainability
ˌən-sə-ˌstā-nə-ˈbi-lə-tē How to pronounce unsustainable (audio)
noun
unsustainably
ˌən-sə-ˈstā-nə-blē How to pronounce unsustainable (audio)
adverb
an unsustainably high rate of growth

Examples of unsustainable in a Sentence

Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
Without that orchestration, human intelligence would be biologically unsustainable. — Bratin Saha, Forbes.com, 21 Aug. 2026 Analysts who spoke to ABC News acknowledged the difficulty in predicting when the most severe effects of the ballooning debt may materialize but warned that regardless of the answer, the current trajectory is unsustainable. — Max Zahn, ABC News, 20 Aug. 2026 Debt hawks have been warning policymakers for some time that the nation’s fiscal path is unsustainable, and the issue is increasingly rising up voters’ agendas in the run-up to midterms later this year. — Eleanor Pringle, Fortune, 20 Aug. 2026 Given the amount of money floating in major college athletics these days, disregard the alarmists who declare that college football is dying, or unsustainable. — Fort Worth Star-Telegram, 19 Aug. 2026 See All Example Sentences for unsustainable

Word History

First Known Use

circa 1677, in the meaning defined above

Time Traveler
The first known use of unsustainable was circa 1677

Rhymes for unsustainable

See All Rhymes for unsustainable

Browse Nearby Words

unsuspicious
unsustainable
unsustained
See all Nearby Words

Cite this Entry

“Unsustainable.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/unsustainable. Accessed 27 Aug. 2026.

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