Definitions

1. verb

to speak indistinctly or in a low voice, often with a grumbling or complaining tone

“She started to mutter to herself when she saw the news about her favorite show being cancelled.”

2. verb

to express discontent or annoyance

“He began to mutter about the long wait at the restaurant.”

3. noun

a low, indistinct sound, especially one of discontent or annoyance

“The mutter of the crowd grew louder as the politician spoke.”

4. noun

a confused or unclear word or phrase

“The mutter of the ancient language was difficult to decipher.”