crumble /ˈkɹʌmbəl/verb 3noun 1forms 4phrases 1 verb3 •To fall apart; to disintegrate.The bread roll crumbled when I tried to slice it; it was too stale.The empire crumbled when the ruler's indiscretions came to light. •To break into crumbs.We crumbled some bread into the water. •To mix (ingredients such as flour and butter) in such a way as to form crumbs.Using your fingers, crumble the ingredients with the fingertips, lifting in an upward motion, until the mixture is sandy and resembles large breadcrumbs. noun1 •A dessert of British origin containing stewed fruit topped with a crumbly mixture of fat, flour, and sugar. formscrumbled · crumbling · crumbles · crumbleth Phrases with crumble crumble upTo make (something) into crumbs.