The Collaborative International Dictionary of English v.0.48:

Paunch \Paunch\ (p[add]nch or p[aum]nch; 277), n. [OF. panch,
   pance, F. panse, L. pantex, panticis.]
   1. (Anat.) The belly and its contents; the abdomen; also, the
      first stomach, or rumen, of ruminants. See Rumen.
      [1913 Webster]

   2. (Naut.) A paunch mat; -- called also panch.
      [1913 Webster]

   3. The thickened rim of a bell, struck by the clapper.
      [1913 Webster]

   4. A noticeably protruding belly; a potbelly.
      [PJC]

   Paunch mat (Naut.), a thick mat made of strands of rope,
      used to prevent the yard or rigging from chafing.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Paunch \Paunch\, v. t. [imp. & p. p. Paunched (p[add]ncht or
   p[aum]ncht); p. pr. & vb. n. Paunching.]
   1. To pierce or rip the belly of; to eviscerate; to
      disembowel. --Shak.
      [1913 Webster]

   2. To stuff with food. [Obs.] --Udall.
      [1913 Webster]

WordNet (r) 3.0 (2006):

paunch
    n 1: a protruding abdomen [syn: belly, paunch]

Moby Thesaurus II by Grady Ward, 1.0:

41 Moby Thesaurus words for "paunch":
   abdomen, abomasum, bay window, beerbelly, belly, bowel,
   breadbasket, corporation, craw, crop, diaphragm, disembowel, draw,
   embonpoint, first stomach, gizzard, gullet, gut, honeycomb stomach,
   kishkes, manyplies, maw, midriff, omasum, pot, potbelly, potgut,
   psalterium, pusgut, rennet bag, reticulum, rumen, second stomach,
   spare tire, stomach, swagbelly, third stomach, tum-tum, tummy,
   underbelly, ventripotence