A ridge on a corrugated surface.

Roget 195: contraction, reduction, diminution; decrease of size etc. 36; defalcation, decrement; lessening, shrinking etc. v.; compaction; tabes^†, collapse, emaciation, attenuation, tabefaction^†, consumption, marasmus^†, atrophy; systole, neck, hourglass.    condensation, compression, compactness; compendium etc. 596; squeezing etc. v.; strangulation; corrugation; astringency; astringents, sclerotics; contractility, compressibility; coarctation^†.    inferiority in size.    ... show more

Roget 256: roughness etc. adj.; tooth, grain, texture, ripple; asperity, rugosity^†, salebrosity^†, corrugation, nodosity^†; arborescence^† etc. 242; pilosity^†.    brush, hair, beard, shag, mane, whisker, moustache, imperial, tress, lock, curl, ringlet; fimbriae, pili, cilia, villi; lovelock; beaucatcher^†; curl paper; goatee; papillote, scalp lock.    plumage, plumosity^†; plume, panache, crest; feather, tuft, fringe, toupee.    wool, velvet, plush, nap, pile, floss, fur, down; byssus^†, moss, bur; fluff.    knot (convolution) 248.    ... show more

Roget 258: fold, plicature^†, plait, pleat, ply, crease; tuck, gather; flexion, flexure, joint, elbow, double, doubling, duplicature^†, gather, wrinkle, rimple^†, crinkle, crankle^†, crumple, rumple, rivel^†, ruck^†, ruffle, dog's ear, corrugation, frounce^†, flounce, lapel; pucker, crow's feet; plication^†.    ... show more

Roget 61: derangement etc. v.; disorder etc. 59; evection^†, discomposure, disturbance; disorganization, deorganization^†; dislocation; perturbation, interruption; shuffling etc. v.; inversion etc. 218; corrugation etc. (fold) 258; involvement.    interchange etc. 148.    ... show more

The act of shaping into parallel ridges and grooves.