sustainable

sustainable — adjective

1. able to keep going at the same level or rate over a long period without failing

1.形容詞B2
釋義

able to keep going at the same level or rate over a long period without failing or running out

例句

The company's rapid growth was not sustainable, so the board decided to slow down.

be + not + sustainable — common negative pattern

Ayesha knew her work pace was unsustainable after working twelve-hour days for a month.

unsustainable — negative prefix form

同義詞
  • maintainable

    less common; focuses on ability to keep something at a certain level

  • viable

    emphasises that something can succeed, not just continue

  • workable

    informal; suggests a practical solution rather than a long-term rate

反義詞

文法句型

sustainable + noun (growth, pace, level)

be sustainable

be not sustainable / be unsustainable

用法筆記

Often negated: unsustainable is very common when talking about growth rates, work hours, debt levels, or business models that cannot continue.

常見錯誤

❌The economic development is sustainable for the environment.
✅The economic development is environmentally sustainable.
💡sustainable already includes the idea of long-term continuation; to specify the environmental meaning, add environmentally or use sense 2.

2. relating to practices or products that protect natural resources from being exha

2.形容詞B1
釋義

relating to practices or products that protect natural resources from being exhausted or permanently harmed, so they remain available long into the future

例句

The city council voted to invest more in sustainable energy sources like solar power.

sustainable + energy sources — common collocation

Mauricio switched to a brand of sustainable clothing made from recycled materials.

同義詞
  • eco-friendly

    informal; narrower — focuses on low environmental harm, not long-term continuation

  • green

    very informal; broad positive meaning about environmental values

  • renewable

    different meaning — describes energy sources that naturally replenish (sun, wind), not the system as a whole

反義詞
  • unsustainable

    direct negative — describes practices that deplete resources

  • harmful

    broader; does not imply resource depletion specifically

文法句型

sustainable + noun (development, energy, agriculture)

be sustainable

environmentally sustainable

用法筆記

This is the more frequent sense in modern English. Very common before nouns: sustainable development, sustainable energy, sustainable food, sustainable living. The adverb environmentally often precedes it for clarity (e.g. environmentally sustainable farming). The rejected lifestyle-only sense from Merriam-Webster is fully covered here.

常見錯誤

❌Solar panels are sustainable because they do not pollute the air.
✅Solar panels provide sustainable energy because sunlight is a renewable resource.
💡sustainable describes systems that can continue long-term without depleting resources, not just the absence of pollution.