Longevity escape velocity

In the life extension movement, longevity escape velocity (LEV), actuarial escape velocity or biological escape velocity is a hypothetical situation in which one's remaining life expectancy (not life expectancy at birth) is extended at a faster rate than the time that is passing. For example, in a given year in which longevity escape velocity would be maintained, medical advances would increase people's remaining life expectancy more than the year that just went by.

Source: Wikipedia — Longevity escape velocity (CC BY-SA 4.0)