1. (

• crumble ,
• crumple ,
• tumble ,
• break_down ,
• collapse ,

) fall apart; "the building crumbled after the explosion"; "Negotiations broke down" ;

2. (

• crumble ,
• fall_apart ,

) break or fall apart into fragments; "The cookies crumbled"; "The Sphinx is crumbling" ;

3. (

• decay ,
• crumble ,
• dilapidate

) fall into decay or ruin; "The unoccupied house started to decay" ;