* once, one time.
* for one thing.
* (used to emphasize a sentence which follows:)
Bir defa kendisiyle görüş, sonra konuşalım.
Just see him and then we'll talk.
* (used at the conclusion of a sentence which describes a fait accompli:)
Bunu bozduk bir defa, artık iflah olmaz.
We've broken this and now it's beyond repair.