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]

Moby Thesaurus II by Grady Ward, 1.0:

152 Moby Thesaurus words for "pucker":
   abbreviate, agitation, all-overs, angst, anxiety, anxiety hysteria,
   anxiety neurosis, anxious bench, anxious concern, anxious seat,
   anxiousness, apprehension, apprehensiveness, befuddlement,
   bewilderment, bother, botheration, cankerworm of care, care, chaos,
   circumscribe, cloud, coarct, cocker, cockle, compact, compress,
   concentrate, concern, concernment, condense, confusion,
   consolidate, constrict, constringe, contract, corrugate,
   corrugation, cramp, crankle, crease, crimp, crimple, crinkle,
   crinkling, crumple, curtail, daze, decrease, discombobulation,
   discomfiture, discomposure, disconcertion, disorder,
   disorganization, disorientation, disquiet, disquietude, distress,
   disturbance, dither, draw, draw in, draw together, dread,
   embarrassment, fear, flap, flummox, flurry, fluster, flusteration,
   flustration, flutter, fog, fold, foofaraw, foreboding,
   forebodingness, frenzy, fret, fuddle, fuddlement, furrow, fuss,
   gather, haze, inquietude, jumble, knit, knot, lather, malaise,
   maze, mess, misgiving, mist, muddle, muddlement, narrow,
   nervous strain, nervous tension, nervousness, overanxiety,
   perplexity, perturbation, pins and needles, pleat, pother,
   pucker up, purse, reduce, ridge, rimple, ripple, rivel, ruche,
   ruck, ruckle, ruffle, rumple, screw up, shirr, shirring, shorten,
   shuffle, solicitude, solidify, squeeze, stew, strain, strangle,
   strangulate, suspense, sweat, swivet, tension, tighten, tizzy,
   trouble, tuck, twitter, twitteration, uneasiness, unquietness,
   unsettlement, upset, vexation, wimple, wrinkle, wrinkling, zeal