grumbl

v. i. [ imp. & p. p. Grunbled p. pr. & vb. n. Grumbling ] [ Cf. LG. grummeln, grumen, D. grommelen, grommen, and F. grommeler, of German origin; cf. W. grwm, murmur, grumble, surly. √35. Cf. Grum, Grim. ] 1. To murmur or mutter with discontent; to make ill-natured complaints in a low voice and a surly manner. [ 1913 Webster ]

L'Avare, not using half his store,
Still grumbles that he has no more. Prior. [ 1913 Webster ]

2. To growl; to snarl in deep tones; as, a lion grumbling over his prey. [ 1913 Webster ]

3. To rumble; to make a low, harsh, and heavy sound; to mutter; as, the distant thunder grumbles. [ 1913 Webster ]