(transitive) To rumple; to press into wrinkles by crushing together. / (transitive) To cause to collapse. / (intransitive) To become wrinkled. / (intransitive, figuratively) To collapse.

A crease, wrinkle, or irregular fold.

simple past tense and past participle of crumple

Squeezed into a compact mass by irregular folds.

plural of crumple

The act by which something crumples. / A crumpled shape or structure. / A small crump

present participle of crumple

plural of crumpling

A structural feature of an automobile/motor car designed to compress during an accident and absorb impact energy.

(intransitive) To become crumpled or messily folded up. / (transitive) To crumple or messily fold (something).