Zwieback (German, "two bakings") is a crisp, sweetened rusk bread. It is made with an egg-enriched bread that is baked, sliced thin, and baked again until crisp.
The term is also used for a yeasted Mennonite roll, which is no longer twice-baked and is shaped to have a small ball on top of the roll, much like traditional French brioche à tête. These rolls are an important part of the Faspa meal tradition in Mennonite society.
Word origins
German, zwei "two", back, from backen "to cook". Note the similarity to the French term biscotte and the Italian biscotto; in the French case, the cognate term biscuit came to mean any small crisp pastry.