Mump (?), v. i. [Akin to mumble; cf. D. mompen to cheat; perh. orig., to whine like a beggar, D. mompelen to mumble. See Mumble, Mum, and cf. Mumps.] 1. To move the lips with the mouth closed; to mumble, as in sulkiness.
He mumps, and lovers, and hangs the lip. Taylor, 1630.
2. To talk imperfectly, brokenly, or feebly; to chatter unintelligibly.
3. To cheat; to deceive; to play the beggar.
And then when mumping with a sore leg,... canting and whining. Burke.
4. To be sullen or sulky.