crumple up

/K R AH1 M P AH0 L AH0 P/
verb
  1. 1

    (intransitive) To become crumpled or messily folded up.

  2. 2

    (transitive) To crumple or messily fold (something).

  3. 3

    (intransitive, figurative, by extension) To collapse; to give up and fold in a stressful situation.