English Reference

Word

unsustainable

Phoneticsun·sus·tain·able

US/ˌənsəˈsteɪnəbəɫ/

UK/ʌnsəstˈeɪnəbəl/

Definition

adj. describing something that cannot continue for a long time because it uses too many resources or causes damage.

adj. incapable of being maintained at the current rate or level; specifically relating to practices that deplete natural resources or exceed economic capacity.

Examples

“The current level of spending is unsustainable for our family.”

“Environmentalists argue that our reliance on single-use plastics is unsustainable and will lead to a waste crisis.”

“The rapid expansion of the tech bubble was fueled by unsustainable debt levels that eventually triggered a market correction when investors demanded actual profitability.”

Examples

simple

“The current level of spending is unsustainable for our family.”

contextual

“Environmentalists argue that our reliance on single-use plastics is unsustainable and will lead to a waste crisis.”

complex

“The rapid expansion of the tech bubble was fueled by unsustainable debt levels that eventually triggered a market correction when investors demanded actual profitability.”

Usage

Often used predicatively after 'be' or 'become'; frequently modifies nouns like 'growth', 'development', or 'debt'.

Real-World Examples

“Others can detect a fake lowered pitch; it's unsustainable and probably won't improve how women see you.”
Phys.org · 18 Aug 2026
“Unsustainable surfing, meanwhile, may cause problems in the ecosystem.”
Smithsonian Magazine · 6 Aug 2026

This entry

Level
B2 · Upper Intermediate
Frequency
Occasional
Updated

Scan code

englishreference.com/q/unsustainable

English Reference