• capable of being sustained, maintainable
• if a plan, method, or system is sustainable, it can be continued at the same level of activity or pace without harming its efficiency and the people affected by it.
• you use sustainable to describe the use of natural resources when this use is kept at a steady level and is not likely to damage the environment.
• farming methods that serve to preserve the soil quality for future agricultural use (e.g. through non-use of chemical preparations, crop rotation, etc.)
• method of planning city growth and economic development in order to avoid depletion of natural resources
• cannot be continued, cannot be sustained, can not be kept going