capable of being supported or upheld, as by having its weight borne from below.
2.
pertaining to a system that maintains its own viability by using techniques that allow for continual reuse: sustainable agriculture. Aquaculture is a sustainable alternative to overfishing.
3.
able to be maintained or kept going, as an action or process: a sustainable negotiation between the two countries.
4.
able to be confirmed or upheld: a sustainable decision.
5.
able to be supported as with the basic necessities or sufficient funds: a sustainable life.
(of economic development, energy sources, etc) capable of being maintained at a steady level without exhausting natural resources or causing severe ecological damage: sustainable development
1610s, "bearable," from sustain + -able. Attested from 1845 in the sense "defensible;" from 1965 with the meaning "capable of being continued at a certain level." Sustainable growth is recorded from 1965. Related: Sustainability (1972).