Grum·ble v. i. [imp. & p. p. Grunbled p. pr. & vb. n. Grumbling ]
 1. To murmur or mutter with discontent; to make ill-natured complaints in a low voice and a surly manner.
 L'Avare, not using half his store,
 Still grumbles that he has no more.   --Prior.
 2. To growl; to snarl in deep tones; as, a lion grumbling over his prey.
 3. To rumble; to make a low, harsh, and heavy sound; to mutter; as, the distant thunder grumbles.
 grumbling
      adj 1: continuous full and low-pitched throbbing sound; "the
             rumbling rolling sound of thunder" [syn: rumbling]
      2: muttering discontentedly; "the grumbling boarders requested
         a meeting with the cook"
      n 1: a loud low dull continuous noise; "they heard the rumbling
           of thunder" [syn: rumble, rumbling, grumble]
      2: a complaint uttered in a low and indistinct tone [syn: grumble,
          murmur, murmuring, mutter, muttering]