The span of life of a living thing; lifetime (often expressed in years).
猫の平均寿命は約15年だ。
The average lifespan of a cat is about 15 years.
人間の寿命は医療によって延びてきた。
Human lifespans have increased thanks to medical advances.
彼女は長寿で有名な地域に住んでいる。
She lives in a region known for longevity.
The service life of an object (battery, light bulb, machine); how long something functions usefully.
このバッテリーの寿命は約2年だ。
The lifespan of this battery is about two years.
電球の寿命が切れたので交換した。
The light bulb burned out, so I replaced it.
自動車の寿命を延ばすために定期点検が重要だ。
Regular inspections are important to extend a car's service life.