LONGEVITY

n. long life; length of life

Longevity is a term that generally refers to 'long life' or 'great duration of life'. Reflections on longevity have usually gone beyond acknowledging the basic shortness of human life and have included thinking about methods to extend life. Longevity has been a topic not only for the scientific community but also for writers of travel, science fiction and utopian novels. There are many difficulties to authenticate the longest human lifespan ever, because of inaccurate birth statistics in the past; though fiction, legend, and mythology have proposed or claimed vastly longer lifespans in the past or future and longevity myths frequently allege them to exist in the present.
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Noun
1. duration of service; "her longevity as a star"; "had unusual longevity in the company"
(synonym) length of service
(hypernym) longness
2. the property of being long-lived
(synonym) seniority
(hypernym) oldness

(n.)
Long duration of life; length of life.
  

Lifespan. (With increasing longevity, women will soon be postmenopausal for one third of their lives).