Webster’s Revised Unabridged Dictionary · 1913
Corrugate
Cor′ru·gate (k?r′r?-g?t), a. [L. corrugatus, p. p. of corrugare; cor-+ rugare to wrinkle, ruga wrinkle; of uncertain origin.] Wrinkled; crumpled; furrowed; contracted into ridges and furrows.
Cor′ru·gate (-g?t), v. t. [imp. & p. p. Corrugated (-g?′t?d); p. pr. & vb. n. Corrugating (-g?′t?ng).] 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.
Corrugated iron, sheet iron bent into a series of alternate ridges and grooves in parallel lines, giving it greater stiffness. — Corrugated paper, a thick, coarse paper corrugated in order to give it elasticity. It is used as a wrapping material for fragile articles, as bottles.