Question 1

What does "once and for all" mean?

Accepted Answer

Finally and definitively; so that the matter will not need to be revisited.

Question 2

How do you use "once and for all" in a sentence?

Accepted Answer

Let's settle this dispute once and for all.

Question 3

Is "once and for all" formal or informal?

Accepted Answer

"once and for all" is register-neutral — appropriate in both casual and formal contexts. Used to emphasise that a decision or action is final and intended to resolve a matter permanently.