名詞 lifetime:

1. the period during which something is functional (as between birth and death)
   同義詞：life, life-time, lifespan

1. Could you reconcile yourself to a lifetime of unemployment?
   你能甘心一輩子失業(yè)嗎?
2. The government is unlikely to get the bill through within (the lifetime of) this Parliament.
   政府不大可能在本屆國會(會期)內(nèi)通過該項(xiàng)法案。
3. He could not but look up to the sky and sigh deeply when his lifetime of frustrations passed through his mind.
   想起自己坎坷的一生，他不由仰天長嘆。
4. He is a legend in his lifetime for his scientific discoveries.
   他的科學(xué)發(fā)現(xiàn)使他一生成為傳奇人物。
5. It's a once in a lifetime chance.
   這是一生難得的機(jī)會。
6. A lifetime guarantee; lifetime membership.
   終身保障; 終身會員資格
7. I doubt if there will be a female president in this country in my lifetime.
   我懷疑在我有生之年這個(gè)國家會不會出現(xiàn)一位女總統(tǒng)。

life.time

n.（名詞）
The period of time during which an individual is alive.
一生：一個(gè)人生存的一段時(shí)間
The period of time during which property, an object, a process, or a phenomenon exists or functions.
存在期，有效期：某種性質(zhì)、物體、過程或現(xiàn)象存在或起作用的一段時(shí)間
n.attributive.（定語名詞）
Often used to modify another noun:
終生：經(jīng)常用來修飾另一個(gè)名詞：
例句：
a lifetime guarantee; lifetime membership.
終身保障；終身會員資格