From Longman Dictionary of Contemporary Englishunleavenedun‧leav‧ened /ʌnˈlevənd/ adjective DFunleavened bread is flat because it is not made with yeast
Examples from the Corpus
unleavened• MAtse a. The unleavened bread used during the celebration of Passover.• The bricks were formed from unleavened mud, dug from the shallows of a nearby stream. 