crease
Definitions
A line or ridge produced on paper or cloth by folding, pressing, or crushing it.
A marked line on a playing field, such as the area around a goal in lacrosse or hockey.
To make a fold, wrinkle, or line in a smooth surface.
Examples
He carefully ironed his trousers to remove every single crease.
A deep crease appeared on her forehead as she concentrated on the difficult puzzle.
Fold the paper along the crease to ensure the edges align perfectly.