crumple in WordNet English dictionary

1. fall apart
   "the building crumbled after the explosion"; "Negotiations broke down"
   crumble  crumple  tumble  break down  collapse 
   
2. fold or collapse
   "His knees buckled"
   buckle  crumple 
   
3. to gather something into small wrinkles or folds
   "She puckered her lips"
   pucker  rumple  cockle  crumple  knit 
   
4. become wrinkled or crumpled or creased
   "This fabric won't wrinkle"
   rumple  crumple  wrinkle  crease  crinkle