To scrunch means to squeeze or crush something together so that it makes a noise or changes shape.
Scrunching can be a little bit noisy and can make things change shape.
Examples:
I am scrunching the paper into a ball.
She is scrunching her face in a funny way.
The cat is scrunching up its body to fit into the box.
I heard someone scrunching a bag of chips in the kitchen.
He was scrunching the leaves so hard, they made a big noise.
Stop scrunching my hat, it's not a toy!