yī​láo​yǒng​yì

once and for all

一劳永逸 一勞永逸 yī​láo​yǒng​yì
once and for all adverb
To put in the effort once so that one can enjoy permanent ease; to settle a matter forever by doing it thoroughly one time.

Frequency

Movie subtitles
1.61 per million appears in 1% of films
Written text
0.925 per million

Sources