Synonyms for grumble
verb
To complain
whine, protest, fuss; see complain 1.
To growl
snarl, gnarl, gnarr*, snap, bark, grunt, mutter, rumble, croak, roar, splutter, snuffle, whine.
To mutter
murmur, mumble, whine; see mutter 2.
See grumble in Webster's New World Roget's A-Z Thesaurus II
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