subsistence

Short definition from Wiktionary

Noun

1. 1
   Real being; existence.
2. 2
   The act of maintaining oneself at a minimum level.
3. 3
   Inherency.
4. 4
   Something (food, water, money, etc.) that is required to stay alive.
5. 5
   Embodiment or personification or hypostasis of an underlying principle or quality.