crumble up

crumble something up (into something)

to crunch up or break up something into pieces. Now, crumble the dried bread up into crumbs. Crumble up the bread into crumbs.
See also: crumble, up

crumble up

to break up into little pieces. The cake, which was very dry, crumbled up when I tried to cut it. The paper of the old book crumbled up when I turned the pages.
See also: crumble, up