But of all these biases, mumbling is the subtle, underappreciated one.
As many of these performances prove, mumbling often coincides with good acting.
Sure, there are plenty of Republicans mumbling the standard talking points, but few, if any, are capturing the public imagination.
early 14c., momelen, "to eat in a slow, ineffective manner" (perhaps "to talk with one's mouth full"), probably frequentative of interjection mum. The -b- is excrescent. Meaning "to speak indistinctly" is from mid-14c. Related: Mumbled; mumbling.
1902, from mumble (v.).