crum•blePronunciation: (krum'bul), [key]
—v., -bled, -bling,
to break into small fragments or crumbs.
to fall into small pieces; break or part into small fragments.
to decay or disintegrate gradually: The ancient walls had crumbled.
a crumbly or crumbled substance.
bits of crisp bacon, bread, etc., added to other foods, esp. as a topping.
3. Brit. Dial.
crumb; particle; fragment.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.