v. & n.
--v.
1. tr. & intr. break or fall into crumbs or fragments.
2 intr. (of power, a reputation, etc.) gradually disintegrate.
--n.
1. Brit. a mixture of flour and fat, rubbed to the texture of breadcrumbs and cooked as a topping for fruit etc. (apple crumble; vegetable crumble).
2 a crumbly or crumbled substance.
Etymology: ME f. OE, formed as CRUMB