lifetime

A lifetime is the whole stretch of years from birth to death. In her lifetime, a lifetime of work, it lasted a lifetime.

It is used to say how long something continued or how much somebody saw: within his lifetime, the changes of a lifetime. The phrase the chance of a lifetime means an opportunity that will not come again, and once in a lifetime is its adjective form. Note lifetime guarantee, which sounds generous and usually means the expected life of the product rather than yours, and that lifespan is the technical term for how long something lives.

Phrases it lives in

• the chance of a lifetime — an opportunity that will not come round again