1. speaks in a low, unclear way that is difficult to understand
Usage: third person singular present tense of ‘mumble’

1. unclear speech that is difficult to understand
Usage: plural form

Examples

• She mumbles when she’s nervous.
• He always mumbles his answers during class.
• The old man mumbles to himself while walking.
• I can’t understand what she mumbles under her breath.
• His mumbles were barely audible from across the room.
• The teacher asked him to stop his mumbles and speak clearly.