noun
a low, indistinct, or inarticulate sound
verb
to speak in a low, indistinct manner, often with the mouth partly closed
-
The speaker began to mumble as he struggled to remember his speech.
-
I couldn't hear what she was saying because she was mumbling.
-
Stop mumbling and speak clearly so I can understand you.
-
The wind mumbled through the trees, creating a soothing sound.