life expectancy noun
plural ∼ -cies : the average number of years that a person or animal can expect to live [noncount] ▪ improvements in diet that have resulted in greater life expectancy for many people [count] ▪ calculating the life expectancies of different social groups — often used figuratively ▪ What is the life expectancy of a new computer? [=how long can a new computer be expected to last or be useful?]
