mum

a. [ Of imitative origin. Cf. Mumble. ] Silent; not speaking; as, to keep mum. Thackeray. [ 1913 Webster ]

The citizens are mum, and speak not a word. Shak. [ 1913 Webster ]

mum's the word keep this a secret; don't tell anybody. [ PJC ]

n. Silence. [ R. ] Hudibras. [ 1913 Webster ]

n. [ G. mummere, fr. Christian Mumme, who first brewed it in 1492. ] A sort of strong beer, originally made in Brunswick, Germany. Addison. [ 1913 Webster ]

The clamorous crowd is hushed with mugs of mum. Pope. [ 1913 Webster ]

v. t. [ imp. & p. p. Mumbled p. pr. & vb. n. Mumbling ] [ OE. momelen; cf. D. mompelen, mommelen, G. mummelen, Sw. mumla, Dan. mumle. Cf. Mum, a., Mumm, Mump, v. ] 1. 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. [ 1913 Webster ]

Peace, you mumbling fool. Shak. [ 1913 Webster ]

A wrinkled hag, with age grown double,
Picking dry sticks, and mumbling to herself. Otway. [ 1913 Webster ]

2. To chew something gently with closed lips. [ 1913 Webster ]

v. t. 1. To utter with a low, inarticulate voice. Bp. Hall. [ 1913 Webster ]

2. To chew or bite gently, as one without teeth. [ 1913 Webster ]

Gums unarmed, to mumble meat in vain. Dryden. [ 1913 Webster ]

3. To suppress, or utter imperfectly. [ 1913 Webster ]

n. A talebearer. [ Obs. ] [ 1913 Webster ]

n. One who mumbles. [ 1913 Webster ]

n. A game played with a pocketknife, the object of which is to throw the knife in any of a vairety of ways (such as over the back), or from various positions, and have it stick in the ground or another surface. Also called mumble-the-peg and mumble peg. [ PJC ]