once and for all

/W AH1 N S AE1 N D F AO1 R AO1 L/
adverb
  1. 1

    Finally, permanently, conclusively.

    โ€œThey replaced the entire door, in hopes of correcting the sticking and squeaking once and for all.โ€

Source: https://en.wiktionary.org/wiki/once%20and%20for%20all