/ ˈmʌmbl; NAmE / verb , noun
■ verb
to speak or say sth in a quiet voice in a way that is not clear
SYN mutter :
[ v ]
I could hear him mumbling to himself.
[ vn ]
She mumbled an apology and left.
[ v speech ]
'Sorry,' she mumbled.
[also v that ]
■ noun
[ usually sing. ] (also mum·bling [ C , usually pl. , U ]) speech or words that are spoken in a quiet voice in a way that is not clear :
He spoke in a low mumble, as if to himself.
They tried to make sense of her mumblings.
••
WORD ORIGIN
Middle English : frequentative of mum (adjective).