If someone crumples, they collapse, for example when they have received a shock. His body crumpled He immediately crumpled to the floor Chance McAllister lay crumpled on the floor
If you crumple something such as paper or cloth, or if it crumples, it is squashed and becomes full of untidy creases and folds. She crumpled the paper in her hand The front and rear of the car will crumple during a collision. Crumple up means the same as crumple. She crumpled up her coffee cup Nancy looked at the note angrily, then crumpled it up and threw it in a nearby wastepaper basket. + crumpled crum·pled His uniform was crumpled, untidy, splashed with mud