pucker
     n : an irregular fold in an otherwise even surface (as in cloth)
         [syn: {ruck}]
     v 1: to gather something into small wrinkles or folds; "She
          puckered her lips" [syn: {rumple}, {cockle}, {crumple},
          {knit}]
     2: draw fabric together and sew it tightly [syn: {gather}, {tuck}]
     3: become wrinkled or drawn together; "her lips puckered" [syn:
         {ruck}, {ruck up}]
Source: WordNet® 2.0