The Collaborative International Dictionary of English v.0.48:

Bellyache \Bel"ly*ache`\, n.
   Pain in the bowels; colic.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Bellyache \Bel"ly*ache`\, v. i.
   to complain, especially in a whining or grumbling manner; to
   gripe.

   Syn: gripe, whine, complain, moan, snivel, grumble, squawk.
        [PJC + WordNet 1.5]

WordNet (r) 3.0 (2006):

bellyache
    n 1: an ache localized in the stomach or abdominal region [syn:
         stomachache, stomach ache, bellyache, gastralgia]
    v 1: complain; "What was he hollering about?" [syn: gripe,
         bitch, grouse, crab, beef, squawk, bellyache,
         holler]