To break into small pieces, usually when something is dry or old; to gradually fall apart.
From Middle English 'cromblen,' possibly related to Middle Dutch 'krummelen.' The word may have Germanic roots and is connected to 'crumb,' showing how breaking into crumbs became 'crumbling.'
The British dessert 'crumble' gets its name because the topping is literally crumbled butter and flour—it's designed to fall apart in your mouth!
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