noun. A lifetime.

noun. The average or maximum length of time an organism, material, or object can be expected to survive or last.

noun. The length of time for which an organism lives.

noun. The length of time for which something exists or is current or valid.

noun. the period during which something is functional (as between birth and death)

"They die within a day; their lifespan is accelerated because time works on them differently, just as time works differently on a Galapagos tortoise and a Rattus rattus."

period  period of time  time period  

afterlife  hereafter  

absorbance  designer/developer  hughcortazzi  joyride  life-span  

lifetime