- 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."Peace, you mumbling fool." [Shak.]"A wrinkled hag, with age grown double, Picking dry sticks, and mumbling to herself." [Otway.]
- To chew something gently with closed lips.
Etymology: OE. momelen; cf. D. mompelen mommelen, G. mummelen, Sw. mumla, Dan. mumle. Cf. Mum (a.) Mumm Mump (v.)