מַצָּה

matstsâh. from מָצַץ in the sense of greedily devouring for sweetness; properly, sweetness; concretely, sweet (i.e. not soured or bittered with yeast); specifically, an unfermented cake or loaf, or (elliptically) the festival of Passover (because no leaven was then used); unleaved (bread, cake), without leaven.