The Collaborative International Dictionary of English v.0.48:

Corrugate \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.
   [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]

The Collaborative International Dictionary of English v.0.48:

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

WordNet (r) 3.0 (2006):

corrugated
    adj 1: shaped into alternating parallel grooves and ridges; "the
           surface of the ocean was rippled and corrugated"

Moby Thesaurus II by Grady Ward, 1.0:

112 Moby Thesaurus words for "corrugated":
   broken, bumpy, canaliculate, canaliculated, chamfered, channeled,
   choppy, coarse, coarse-grained, cockled, cockly, corduroy,
   corduroyed, corrugate, costate, cragged, craggy, creased, crimped,
   crimpy, crinkled, crinkly, cross-grained, crumpled, cut, dadoed,
   engraved, fluted, furrowed, gashed, goffered, gouged, grainy,
   granulated, gravelly, grooved, harsh, homespun, horripilant,
   incised, inequal, ironbound, irregular, jagged, jaggy, jolty,
   knitted, knotted, linsey-woolsey, pimply, pitted, pleated, pocky,
   potholed, puckered, puckery, pursed, pursy, rabbeted, ragged, rank,
   ribbed, ridged, rifled, rimpled, rippled, ripply, rockbound, rocky,
   rough, rough-cast, rough-grained, rough-hewn, rucked, ruffled,
   rugged, rugose, rugous, rumpled, rutted, rutty, saw-toothed,
   sawtooth, scored, scragged, scraggly, scraggy, scratched, serrate,
   serrated, shagged, shaggy, slit, snagged, snaggled, snaggy, stony,
   striated, sulcate, sulcated, textured, troughed, uneven, unkempt,
   unlevel, unpolished, unrefined, unsmooth, ununiform, wimpled,
   wrinkled, wrinkly