Mut"ism (?), n. The condition, state, or habit of being mute, or
without speech. Max Müller.
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.
Wizards that peep, and that mutter.
Is. viii. 19.
Meantime your filthy foreigner will stare, And mutter to himself.
Dryden.