noun (n)

• duration of service(noun.attribute)

  Example:
  Her longevity as a star.
  Had unusual longevity in the company.
  

  Synonym:
  length of service
  

  source: wordnet30
• the property of being long-lived(noun.attribute)

  Synonym:
  seniority
  

  source: wordnet30
• Long duration of life; length of life.(noun)

  source: webster1913