S: WHO – http://www.who.int/mediacentre/news/releases/2016/health-inequalities-persist/en/ (last access: 26 October 2016); AIHW – http://www.aihw.gov.au/deaths/life-expectancy/ (last access: 18 October 2016).
N: 1. life (n): Old English life (dative lif) “animated corporeal existence; lifetime, period between birth and death; the history of an individual from birth to death, written account of a person’s life; way of life (good or bad); condition of being a living thing, opposite of death; spiritual existence imparted by God, through Christ, to the believer,” from Proto-Germanic *libam, properly “continuance, perseverance,” from PIE *leip- “to remain, persevere, continue; stick, adhere”.
expectancy (n): 1590s, from Medieval Latin expectantia, from Latin expectans + -ancy. Related: Expectance.
First Known Use of life expectancy: 1935
2. Life expectancy is an estimate of how many years a person might be expected to live.
3. Estimate of the average number of additional years that a person of a given age can expect to live. The most common measure of life expectancy is life expectancy at birth. Life expectancy is a hypothetical measure. It assumes that the age-specific death rates for the year in question will apply throughout the lifetime of individuals born in that year. The estimate, in effect, projects the age-specific mortality (death) rates for a given period over the entire lifetime of the population born (or alive) during that time. The measure differs considerably by sex, age, race, and geographic location.
S: 1. OED – http://www.etymonline.com/index.php?search=Life+expectancy (last access: 26 October 2016); MW – http://www.merriam-webster.com/dictionary/life%20expectancy (last access: 26 October 2016). 2. SCOTPHO – http://www.scotpho.org.uk/population-dynamics/healthy-life-expectancy/key-points (last access: 18 October 2016). 3. EncBrit – https://global.britannica.com/science/life-expectancy (last access: 26 October 2016).