The process by which something is sustained or upheld.

That sustains, supports or provides sustenance.

plural of sustain

Third-person singular simple present indicative form of sustain

A person or thing that sustains. / (aeronautics) A rocket engine that remains with a spacecraft during its ascent after the separation of the booster engines.

plural of sustainer

The act of sustaining something.

plural of sustainment

plural of sustainability

plural of sustainable