The Collaborative International Dictionary of English v.0.48:

Belch \Belch\, v. i.
   1. To eject wind from the stomach through the mouth; to
      eructate.
      [1913 Webster]

   2. To issue with spasmodic force or noise. --Dryden.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Belch \Belch\, n.
   1. The act of belching; also, that which is belched; an
      eructation.
      [1913 Webster]

   2. Malt liquor; -- vulgarly so called as causing eructation.
      [Obs.] --Dennis.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Belch \Belch\ (b[e^]lch; 224), v. t. [imp. & p. p. Belched
   (b[e^]lch); p. pr. & vb. n. Belching.] [OE. belken, AS.
   bealcan, akin to E. bellow. See Bellow, v. i.]
   1. To eject or throw up from the stomach with violence; to
      eruct.
      [1913 Webster]

            I belched a hurricane of wind.        --Swift.
      [1913 Webster]

   2. To eject violently from within; to cast forth; to emit; to
      give vent to; to vent.
      [1913 Webster]

            Within the gates that now
            Stood open wide, belching outrageous flame.
                                                  --Milton.
      [1913 Webster]

WordNet (r) 3.0 (2006):

belch
    n 1: a reflex that expels gas noisily from the stomach through
         the mouth [syn: belch, belching, burp, burping,
         eructation]
    v 1: expel gas from the stomach; "In China it is polite to burp
         at the table" [syn: burp, bubble, belch, eruct]
    2: become active and spew forth lava and rocks; "Vesuvius erupts
       once in a while" [syn: erupt, belch, extravasate]

Moby Thesaurus II by Grady Ward, 1.0:

68 Moby Thesaurus words for "belch":
   blare, blat, blow open, blow out, bray, break out, burp, burr,
   burst, burst forth, burst out, buzz, cackle, cascade, caw, chirr,
   clang, clangor, clank, clash, craunch, croak, crump, crunch,
   debouchment, discharge, disgorge, dissiliency, eject, eruct,
   eructate, eructation, erupt, eruption, expel, flare-up, gas, grind,
   groan, growl, grumble, gush, hiccup, hurl forth, irrupt, jangle,
   jar, jet, outbreak, outburst, rapids, rasp, rush, scranch, scrape,
   scratch, scrunch, snarl, snore, spate, spew, spout, spurt, torrent,
   twang, volcan, vomit, wind