4682  matstsah  mats-tsaw'

 from 4711 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.

 see HEBREW for 04711