Sustentation :: Sustentation (n.) The act of sustaining, or the state of being sustained; preservation from falling; support; sustenance; maintenance..
Sustentative :: Sustentation (n.) The aggregate of the functions by which a living organism is maintained in a normal condition of weight and growth.
Sustention :: Sustentative (a.) Adapted to sustain, strengthen, or corroborate; as, sustentative citations or quotations..