What is the meaning of sustenance?

noun

• A source of materials to nourish the body.
  • synonyms: nutriment, nourishment, nutrition, aliment, alimentation, victuals
• The financial means whereby one lives.
  • usage: "each child was expected to pay for their keep"; "he applied to the state for support"; "he could no longer earn his own livelihood"
  • synonyms: support, keep, livelihood, living, bread and butter
• The act of sustaining life by food or providing a means of subsistence.
  • usage: "they were in want of sustenance"; "fishing was their main sustainment"
  • synonyms: sustentation, sustainment, maintenance, upkeep