Usage: Longevity has two specific meanings. The first is the length of life, but the noun specifically refers to a life that is already quite long. "She has enjoyed health and longevity" means that her life has extended farther than most in terms of length. In a second context, generally in employment, longevity refers to the length or duration of one's tenure in a certain capacity. Employee bonuses based on longevity are given in larger amounts to those who have spent the most time with the company.
Suggested Usage: It's easy to use the word longevity incorrectly, since it appears by its nature to refer to length. "I didn't enjoy the
Source: YourDictionary