After the fight with her boyfriend, Olivia was left muttering arguments and comments under her breath.
I could not understand what it was that you were muttering about.
The muttering was illegible.Nobody could decipher the illegible scribbles.
He responded to our attempt to get him out of bed with several minutes of incoherent muttering.
Soon as i got out of stage, iwas followed by several paparazzi muttering me wirh questions.
The crew has been muttering about mutiny, sir.
Muttering to oneself is a complex vocal tic
speaking indistinctly and complainingly
3
Uttering, muttering, fluttering, cluttering, and sputtering.
To mumble words indistinctly or in a low tone, often as if talking to oneself.
"Muttering retreats"
Mutter is a noun and a verb.