streusel Syllabification: (streu·sel)Pronunciation: /ˈstro͞ozəl, ˈstroi-/Definition of streusel noun a crumbly topping or filling made from fat, flour, sugar, and often cinnamon. a cake or pastry with a streusel topping. Origin:from German Streusel, from streuen 'sprinkle'streusel in other Oxford dictionaries Definition of streusel in the British & World English dictionary