Simplify the following text for a Grade 12 native English-speaking person.
Original: The word `` longevity '' is sometimes used as a synonym for `` life expectancy '' in demography or to connote `` long life '' , especially when it concerns someone or something lasting longer than expected ( an ancient tree , for example ) .
Simplified: The word `` longevity '' is sometimes used as a synonym for life expectancy or to connote long life , especially when it concerns someone or something lasting longer than expected .