Green’s Dictionary of Slang

mumble v.

SE in slang uses

In compounds

mumble-crust (n.) [SE mumble, to chew softly, as with toothless gums]

a toothless person.

1550		Udall Ralph Roister Doister I iii: And how doth our old beldame here, Madge Mumblecrust?
1577		Misogonus in Farmer (1906) III i: What a talk I heard between Madge Mumblecrust and our Alison.
1602		Dekker Satiromastix III i: Dost thou loue that mother Mumble-crust, dost thou?
1623		Middleton & Rowley Spanish Gypsy II i: Farewell, old greybeard; – adieu mother mumble-crust.
1672		J. Phillips Maronides (1678) 132: Sh’had liv’d five thousand years a Maid; / Now call’d the Goddess mumble-Crust.

mumble-matins (n.)

a priest.

a.1576

Bishop Pilkington Works 26: How can they be learned having none to teach them but Sir John Mumble-matins? [F&H].

mumble-turd (n.)

a term of abuse.

1575

Appius and Virginia in Farmer (1908) 12: And all for Maud mumble-turd, that mangpodding madge.

In phrases

mumbled up (adj.)

(Aus. Und.) to be found not guilty through perjury.

1869

Australasian (Melbourne) 17 July 8/5: [T]o get off by means of perjury is to be mumbled up.