In the fifteenth century, the word crumb meant the part of a loaf of bread that is not the crust; recipes calling for bread often instructed the cook to slice the crust from the loaf and use only the crumb. The word crumb, however, is older than this particular usage, dating back to the tenth century when it referred more generally, as it does again now, to any particle of food that has broken away from something larger. The ultimate source of crumb was a Germanic word, pronounced something like kram, that meant both curled and rounded: from the rounded sense, the word crumb developed, since a crumb is roughly round in shape; from the curled sense, other food words developed, including crumpet and cruller, since these foods were originally curled before being cooked or as a result of being cooked. When crumb first entered English a thousand years ago, it was spelt crum; the b was not added until the sixteenth century (likely to make it resemble words such as limb and comb), and even then the crum spelling remained the usual form until the eighteenth century. This original spelling is still present in crummy, meaning that something is so shoddy it is crumbling to pieces.
The minuscule fragment or speck extracted from a greater entity, commonly a desiccated solid, such as a slice of bread.
To envelop a food item with crumbs, either from bread or crackers. Generally, the comestible is first coated with flour and eggs before being rolled in the crumbs.