from
The Collaborative International Dictionary of English v.0.48
Mutter \Mut"ter\, v. i. [imp. & p. p. {Muttered}; p. pr. & vb.
n. {Muttering}.] [Prob. of imitative origin; cf. L. muttire,
mutire.]
1. To utter words indistinctly or with a low voice and lips
partly closed; esp., to utter indistinct complaints or
angry expressions; to grumble; to growl.
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Wizards that peep, and that mutter. --Is. viii.
19.
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Meantime your filthy foreigner will stare,
And mutter to himself. --Dryden.
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2. To sound with a low, rumbling noise.
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Thick lightnings flash, the muttering thunder rolls.
--Pope.
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