the chance, etc. of a lifetime
of a lifetime
Used to describe something extremely exceptional, important, or enjoyable that isn't likely to occur again. They offered me the chance of a lifetime to travel the world and write about my experiences abroad. That tour around Europe really was the trip of a lifetime!
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.
the chance, etc. of a ˈlifetimea wonderful opportunity, etc. that you are not likely to get again: This is your chance to win the trip of a lifetime!
Farlex Partner Idioms Dictionary © Farlex 2017