LIFETIME

[noun] [C usually singular] - the period of time during which someone lives or something existsShe had devoted a lifetime/half a lifetime to the peace campaign.The lifetime of the car tyres on such poor roads is about three months.We'll see a tremendous lot of technological changes during/in our lifetime.There will not be an opportunity to see the comet again, even in the lifetime of the youngest of us.Winners of the competition will receive the holiday of a lifetime (= the best holiday they will ever have).We've only been here two days, but it seems like a lifetime.The watch is high quality and should last a lifetime.Enter our competition and this once-in-a-lifetime experience could be yours!Marriage is no longer always seen as a lifetime commitment.She won a lifetime/lifetime's supply of toothpaste.