Dictionary:

rimple

  (rĭm'pəl)

A fold; a wrinkle.

To wrinkle or form wrinkles.

[Middle English rimpil, from Old English hrympel.]

noun

A line or an arrangement made by the doubling of one part over another: crease, crimp, crinkle, crumple, fold, pleat, plica, plication, pucker, ruck², rumple, wrinkle. See smooth/rough.

verb

To make irregular folds in, especially by pressing or twisting: crease, crimp, crinkle, crumple, rumple, wrinkle. See smooth/rough.