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.
1647		Newes out of the west 15: [T]hen perboyl’d mumble-crust [i.e. an old woman] had a mighty mind to ’a bin Leo, and ’a roar'd like one.
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.1562

Bishop Pilkington Aggeus and Abdias n.p.: How shall those fathers and husbandes teach, except they be learned? and howe can they be learned, hauinge none to teache them, but sir Ihon mumble matins.

mumble-turd (n.)

a term of abuse.

1575

Appius and Virginia n.p.: My lorde he is neare hand by this at the Church stile, / and al for Maud mumble turde, that mampodding 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.