noun
life expectancy; average life span
Commonly used in demographic and health contexts to refer to the expected number of years a person will live from birth.
日本の平均寿命は世界でもトップクラスです。
Japan's life expectancy is among the highest in the world.
平均寿命が延
As life expectancy increases, the pension system needs to be reviewed.
noun
mean lifetime
Physics term for the average time a particle or system exists before decaying or changing state.
ミュー粒子の平均寿命は約2.2マイクロ秒です。
The mean lifetime of a muon is about 2.2 microseconds.