Available Definitions:
1) a. - Wrinkled; crumpled; furrowed; contracted into ridges and furrows.
2) v. t. - 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.