mutter

mutáter
/_m_t_r/

Verb
Say something in a low or barely audible voice, esp. in dissatisfaction or irritation.

Noun
A barely audible utterance, esp. a dissatisfied or irritated one.

Synonyms
verb. murmur – mumble – grumble – growl – grouse noun. mumble – muttering – murmur – mumbling – grumble – growl