%rugate%

v. t. [ imp. & p. p. Corrugated p. pr. & vb. n. Corrugating ] 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. [ 1913 Webster ]

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. [ 1913 Webster ]

adj. shaped into parallel folds alternately grooved and ridged; as, the surface of the ocean was rippled and corrugated. [ WordNet 1.5 ]

a. [ L. erugatus, p. p. of erugare to smooth; e out + ruga wrinkle. ] Freed from wrinkles; smooth. [ 1913 Webster ]

v. t. [ L. irrugatus, p. p. of irrugare to wrinkle. ] To wrinkle. [ Obs. ] [ 1913 Webster ]