The Collaborative International Dictionary of English v.0.48:

Crumble \Crum"ble\ (kr[u^]m"b'l), v. t. [imp. & p. p. Crumbled
   (kr[u^]m"b'ld); p. pr. & vb. n. Crumbling
   (kr[u^]m"bl[i^]ng).] [Dim. of crumb, v. t., akin to D.
   kruimelen G. kr["u]meln.]
   To break into small pieces; to cause to fall in pieces.
   [1913 Webster]

         He with his bare wand can unthread thy joints,
         And crumble all thy sinews.              --Milton.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

crumbled \crumbled\ adj.
   broken into small fragments; as, crumbled cookies.

   Syn: fragmented.
        [WordNet 1.5]