1. (v.) To speak with the lips partly closed, so as to render the sounds inarticulate and imperfect; to utter words in a grumbling indistinct manner, indicating discontent or displeasure; to mutter.

2. (v.) To chew something gently with closed lips.

3. (v. t.) To utter with a low, inarticulate voice.

4. (v. t.) To chew or bite gently, as one without teeth.

5. (v. t.) To suppress, or utter imperfectly.

aspirate aspiration bark bated breath bawl bellow bite blare blat blubber boom bray breath breathe breathy voice buzz cackle champ chant chaw chew chew the cud chew up chirp chomp coo crow drawl drone droning exclaim exhalation flute fumble gabble gasp gibber gibbering gnash gnaw grind growl grunt gum hammer hiss jabber jibber keen lilt limp little voice low voice maffle masticate maunder maundering mouth mouthing muddle mumbling munch murmur murmuration murmuring mussitate mutter muttering nibble pant pipe roar rumble ruminate rumor scream screech shriek shuffle sibilate sigh sing snap snarl snort sob soft voice speak speak incoherently splutter sputter squall squawk squeal stage whisper stammer still small voice stumble stutter susurrate susurration susurrus swallow talk thunder trumpet twang underbreath undertone utter verbalize vocalize voice wail warble whine whisper whispering yap yawp yell yelp