The Collaborative International Dictionary of English v.0.48:

Pot-belly \Pot"-bel`ly\, n.
   A protuberant belly.
   [1913 Webster]

Moby Thesaurus II by Grady Ward, 1.0:

49 Moby Thesaurus words for "potbelly":
   abdomen, abomasum, bay window, beerbelly, belly, blimp,
   breadbasket, corporation, craw, crop, diaphragm, embonpoint, fatty,
   first stomach, gizzard, gullet, gut, heavy, heavyweight, hippo,
   honeycomb stomach, kishkes, lump, manyplies, maw, midriff, omasum,
   paunch, pod, pot, potgut, psalterium, pusgut, rennet bag,
   reticulum, roly-poly, rumen, second stomach, spare tire, stomach,
   swagbelly, third stomach, tub, tub of lard, tum-tum, tummy, tun,
   underbelly, ventripotence