rug-, rugo- +

1. A small steep-sided watercourse or gulch with a nearly flat floor: usually dry except after heavy rains.
2. Etymology: "a watercourse, a dry streambed"; from about 1845, a California word, from American Spanish, from Spanish, "rivulet, small stream"; from Latin arrugia, "shaft" or "pit in a gold mine"; apparently a compound of ad-, "to" + ruga, "wrinkle".

1. To fold into parallel ridges and troughs, or to fold something; such as, a sheet of cardboard into parallel ridges and troughs.
2. Etymology: from Latin corrugatus, past participle of corrugare, "to wrinkle"; from com-, cor-, "together, with" + rugare. "to wrinkle".

A reference to a shape of alternating parallel grooves and ridges: "Cardboard boxes maintain their shape because they are reinforced with a corrugated layer inside the two flat-outer surfaces."

Formed or shaped into wrinkles, folds, or into alternating ridges and grooves.

1. A muscle which contracts the skin of the forehead into wrinkles.
2. A muscle that draws together the skin, causing it to wrinkle.

To wrinkle.

A fold, crease, ridge, or wrinkle; for example, mucous membrane.

Characteristic folds of the gastric mucosa; especially, evident when the stomach is contracted.

The interlacing folds of the mucosa that produce a honeycomb appearance in the interior of the gallbladder.

Having alternate ridges and depressions; wrinkled.

The observation and study of the patterns of the grooves, wrinkles, and ridges (rugae) of the palate to identify individual patterns.

1. Having many wrinkles or creases; ridged or wrinkled; deeply wrinkled.
2. A reference to, or description of, a leaf or other plant part that has a surface of alternating depressions and ridges.

A wrinkled state or condition.

Wrinkled; marked by wrinkles.

Finely and irregularly wrinkled; such as, certain mushroom caps.