once and for all

once and for all

if you do something once and for all, you finish doing it so that it does not have to be dealt with again. I'm fed up with arguing about this - let's just settle this argument once and for all. He claims his photographs prove once and for all that UFOs do exist.

See also: all, once

---

---

once and for all

completely and finally. I wish we could settle the matter once and for all.

See also: all, once