longevity

noun

Etymology: Early 17th century, learned borrowing from Latin longaevitās, from longaevus (“ancient, aged”) + -itās. The first part is related to English long and this association led to the alternative pronunciation with /ŋ/.

1. The quality of being long-lasting, especially of life.

   “Grandpa had incredible longevity: he lived to be 105 years old!”

   “This 142-year-old tiny ex-LNWR SB [signal box, at Batley] is an amazing survivor, probably owing its longevity to its location alongside a level crossing. Indeed it started life as a gate box with the delightful name of Lady Ann's Crossing.”

2. Duration over time; persistence.

   “A ‘postdating’ is an example of the use of a lexical item at a later date than currently recorded and these are important in establishing the longevity of use of a term and whether or not it has become obsolete.”