lon·gev·i·ty 
(lŏn-jĕvĭ-tē, lôn-)
(lŏn-jĕvĭ-tē, lôn-)n. pl. lon·gev·i·ties
1.
a. Long life; great duration of life: His longevity vexed his heirs.
b. Length or duration of life or viability: comparing the longevity of men and women; factors that affect the longevity of seeds.
2. Long duration or continuance, as in an occupation: had unusual longevity in the company; her longevity as a star.
[Late Latin longaevitās, from Latin longaevus, ancient : longus, long; see del-1 in the Appendix of Indo-European roots + aevum, age; see aiw- in the Appendix of Indo-European roots.]
lon·gevous (-jēvəs) adj.