Corrugate

Webster's Dictionary of the English Language

·adj Wrinkled; crumpled; furrowed; contracted into ridges and furrows.

II. Corrugate ·vt To form or shape into wrinkles or folds, or alternate ridges and grooves, as by drawing, contraction, pressure, bending, or otherwise; to Wrinkle; to purse up; as, to corrugate plates of iron; to corrugate the forehead.