Unsustainable: meaning, definitions and examples

Used to describe something that cannot be maintained or continued over the long term, often due to environmental, economic, or social reasons.

• The company's rapid expansion was considered unsustainable, leading to financial instability.
• The current rate of deforestation is unsustainable and will lead to severe environmental consequences.

Used to describe a position, opinion, or situation that cannot be defended or held, often in debates, arguments, or discussions. Has a negative connotation.

• Her position on the issue became untenable after new evidence was presented.
• The old fort's strategic position was untenable, leading the troops to retreat.

Used when something lacks justification or cannot be supported or backed up, often in the context of arguments, evidence, or claims. Can have a negative connotation.

• His claims about the project being completed ahead of schedule are unsupportable given the current progress.
• The theory was unsupportable by the available scientific evidence.

Use this word when referring to practices, processes, or systems that cannot be maintained over the long term without causing harm or depletion of resources.

• The company's business model is unsustainable due to its high carbon emissions.
• Relying on fossil fuels is unsustainable for the planet.

This word is suitable for situations involving ideas, arguments, or structures that are fundamentally flawed or unreliable.

• His argument was unsound and failed to convince the jury.
• The building's foundation is unsound and poses a safety risk.

Best used when referring to positions, situations, or theories that are impossible to defend or justify.

• His political stance became untenable after the corruption scandal.
• The theory is scientifically untenable.

Appropriate for describing projects, plans, or ideas that are not feasible or practical to carry out.

• The startup’s financial plan is unviable without significant investment.
• Building a highway through the national park is economically unviable.