The Collaborative International Dictionary of English v.0.48:

zipper \zip"per\, n.
   1. a device for locking together two toothed edges by means
      of a sliding tab.

   Syn: slide fastener, zip, zip-fastener.
        [WordNet 1.5]

WordNet (r) 3.0 (2006):

zipper
    n 1: a fastener for locking together two toothed edges by means
         of a sliding tab [syn: slide fastener, zip, zipper,
         zip fastener]
    v 1: close with a zipper; "Zip up your jacket--it's cold" [syn:
         zip up, zipper, zip] [ant: unzip]

Moby Thesaurus II by Grady Ward, 1.0:

70 Moby Thesaurus words for "zipper":
   articulate, bang, bar, barricade, batten, batten down, bolt,
   buckle, butt, button, button up, choke, choke off, clap, clasp,
   cleat, clip, close, close up, constrict, contain, contract, cover,
   dovetail, fasten, fold, fold up, hasp, hinge, hitch, hook, jam,
   joint, key, latch, lock, lock out, lock up, miter, mortise, nail,
   occlude, padlock, peg, pin, plumb, rabbet, rivet, scarf, screw,
   seal, seal off, seal up, secure, sew, shut, shut the door, shut up,
   skewer, slam, snap, squeeze shut, staple, stick, stitch, strangle,
   tack, toggle, wedge, zip up