MUMBLE v. 2 definitions
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.…
SMACK v.
To open, as the lips, with an inarticulate sound made by a quick compression and separation of the parts of the mouth; to make a noise with, as the lips, by separating them in the act of kissing or after tasting. Drinking off the cup, and smacking his lips with an air of ineffable relish. Sir W. Scott.…