noun (n)

• activity involved in maintaining something in good working order(noun.act)

  Synonym:
  care, maintenance
  

  source: wordnet30
• the act of sustaining life by food or providing a means of subsistence(noun.act)

  Synonym:
  maintenance, sustainment, sustenance, sustentation
  

  source: wordnet30
• The act of keeping up, or maintaining; maintenance.(noun)

  source: webster1913