The Collaborative International Dictionary of English v.0.48:

Pucker \Puck"er\, v. t. & i. [imp. & p. p. Puckered; p. pr. &
   vb. n. Puckering.] [From Poke a pocket, small bag.]
   To gather into small folds or wrinkles; to contract into
   ridges and furrows; to corrugate; -- often with up; as, to
   pucker up the mouth. "His skin [was] puckered up in
   wrinkles." --Spectator.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Pucker \Puck"er\, n.
   1. A fold; a wrinkle; a collection of folds.
      [1913 Webster]

   2. A state of perplexity or anxiety; confusion; bother;
      agitation. [Prov. Eng. & Colloq. U. S.]
      [1913 Webster]

WordNet (r) 3.0 (2006):

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