wrin·kle 
(rĭngkəl)
(rĭngkəl)n.
1. A small furrow, ridge, or crease on a normally smooth surface, caused by crumpling, folding, or shrinking.
2. A line or crease in the skin, as from age.
3. A different or unexpected development, action, or idea: "The 1973 War brought a new wrinkle to the face of battle ... the widespread use of rockets and guided missiles" (Bruce Watson).
4. A problem or imperfection: The report had to be revised because of a few wrinkles.
v. wrin·kled, wrin·kling, wrin·kles
v.tr.
1. To make wrinkles or a wrinkle in: My shirt was wrinkled after being so long in the suitcase.
2. To draw up into wrinkles; pucker: wrinkled her nose in disdain.
v.intr.
To form wrinkles.
[Middle English, back-formation from wrinkled, wrinkled, probably from Old English gewrinclod, past participle of gewrinclian, to wind, crease; see wer-2 in the Appendix of Indo-European roots.]
wrinkly adj.