crinkle
🇺🇸
/ˈkrɪŋkl/
🇬🇧
/ˈkrɪŋkl/
to form thin lines or folds, like when you wrinkle a piece of paper or when a smile causes lines on someone's face
When she laughed, her face crinkled with happiness.
a thin line or fold, like the lines you see on crumpled paper or the wrinkles that appear on someone's skin when they smile
The old map had many crinkles from being folded and unfolded so many times.