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

The current trajectory is unsustainable. —James Richardson, Fortune, 30 Jan. 2026

At the same time, many traditional reimbursement and delivery models are proving unsustainable, both financially and clinically. —CBS News, 29 Jan. 2026

This pushes unsustainable agricultural practices versus, for example, organic, regenerative and other more sustainable forms; increases overproduction and thus the waste of food soils and provides incentives to convert more land, which can add to deforestation. —Nick Nuttall, Forbes.com, 28 Jan. 2026

Although the sport has served me well for four decades-plus, the injuries are piling up at a rate that’s becoming unsustainable. —Adam Cohen, Oklahoman, 27 Jan. 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