Definition of crumbles:
(n) :
A dessert of British origin containing stewed fruit topped with a crumbly mixture of fat, flour, and sugar.
(v) :
(transitive) To break into crumbs.
(v) :
(transitive) To mix (ingredients such as flour and butter) in such a way as to form crumbs.
(v) :
(intransitive, often figurative) To fall apart; to disintegrate.
(n) :
A surname.