Do you mean "看破红尘"?
My translation would be "to disillusion in the impure world".
"看破"simply means "to see through". Then what is "红尘"?
Please refer to this link:
http://www.dizang.org/wd/wd/011.htmAccording to the article, "看破红尘" does not have a Buddhist root, rather it reflects the influence of Chinese Taoism philosophy.
"红尘" (which literally means "red dust") first appeared in 《西都赋》by 班固 of western Han dynasty. It was used to describe the crowd, the noise and the prosperity of the capital city Chang An (Now "Xi'an "). But later on, it has been widely used to refer to the materialistic world.
"看破红尘" initially means a person becomes tired of living in a rich yet meaningless life and chooses to live as hermit.
However, most people think this expression originated from Buddhism, and interpreted it accordingly as " to see through the world that is filled with impurity", or simply "to disillussion and to become a buddhist". And this has become the most common understanding and usage of "看破红尘".