I need to finish this once and for all.
once and for all
idiomConclusively, finally, permanently.
She deleted his number once and for all, knowing she would never call him again.
The treaty was signed once and for all, ending centuries of bitter conflict between the two neighboring nations.
- 01
all at once
Unexpectedly; without warning; all of a sudden.
- 02
for this once
On this particular occasion, to make an exception
- 03
once again
Again, once more, one more time.
- 04
once in a blue moon
Very rarely; very infrequently.
- 05
once in a while
Occasionally; sometimes.
- 06
once or twice
A small, indefinite number of times.