To crinkle means to wrinkle or fold something into small creases and lines, or to make a soft crackling sound. When you crumple a piece of paper in your hand, it crinkles into an irregular pattern of tiny folds. A dry leaf crinkles under your feet, making that satisfying crackling noise.

The word often describes gentle, small-scale wrinkling rather than big, dramatic folds. When someone smiles genuinely, the skin around their eyes might crinkle into little laugh lines. Gift wrap crinkles as you tear it open. A crisp dollar bill stays smooth, but an old one has crinkles from being folded and handled so many times.

You'll also hear crinkle describe sounds: cellophane wrappers crinkle loudly in quiet places like libraries or movie theaters, and aluminum foil crinkles when you scrunch it up.