unsustainable

[uhn-suh-stey-nuh-buhl]

adjective

1. not sustainable; not to be supported, maintained, upheld, or corroborated.

Other Word Forms

• unsustainably adverb

Word History and Origins

Origin of unsustainable¹

1670–80; un- ¹ + sustainable ( def. )

Example Sentences

By embedding a helper enzyme, carbonic anhydrase, into a porous titania structure, the researchers enabled the system to work in a simple bicarbonate solution — similar to sparkling water — without unsustainable additives.

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They call out the industry’s tired shapes, implacable business systems, and unsustainable waste, but in ways that celebrate imagination.

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While it may not have been a breakthrough, it was an acknowledgement by both sides that the existing situation was unsustainable.

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I’ve been watching the AI bubble inflate for months now — the unsustainable burn rates, the pilot projects that went nowhere, the startups that couldn’t explain their unit economics.

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Besides his bearish opinion on tech, given his stance on inflation and unsustainable deficits, he also doesn’t like bonds and thinks credit spreads are unjustifiably tight given the deteriorating economic outlook.

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Related Words

• unsuitable 
• untenable