At the end of A Feast for Crows-Chapter 42, Brienne and her group is
hanged by the Brotherhood Without Banners
She screamed a word. Apparently this saved her, since we see her again in the next book.
What was that word?
According to this article, GRRM confirmed:
This can be inferred from the text, since as George said, Brienne was given the choice of two words in AFFC. And we
We do not find out that word in A Dance With Dragons.
From A Wiki of Ice and Fire: