Green’s Dictionary of Slang

shag-bag n.

also shake-bag
[17C SE shag, a rascal]

1. a worthless, shabby person.

[UK]B.E. Dict. Canting Crew n.p.: Shag-bag a poor, shabby Fellow.
[UK]New Canting Dict. [as cit. c.1698].
[UK]Dyche & Pardon New General Eng. Dict. n.p.: Shag-Bag A poor, shabby, mean-spirited, ragged Fellow.
[UK]Bailey Universal Etym. Eng. Dict. [as cit. c.1698].
[UK]Fielding Life of Jonathan Wild (1784) II 176: There were particularly two parties, viz those who wore hats fiercely cocked, and those who preferred the Nab or trencher hat, with the brim flapping over their eyes [...] the latter went by the several names of Wags, Roundheads, Shakebags, Oldnolls.
[UK]Dyche & Pardon New General Eng. Dict. (4th edn).
[UK]Grose Classical Dict. of the Vulgar Tongue n.p.: Shag bag, a poor sneaking fellow; a man of no spirit: a term borrowed from the cock-pit.
[UK]Grose Classical Dict. of the Vulgar Tongue (3rd edn) n.p.: Shag bag, or shake-bag, a poor sneaking fellow; a man of no spirit.
[UK]Lex. Balatronicum [as cit. 1796].
[UK]Crim.-Con. Gaz. 6 Apr. 105/1: I saw Dr King [...] giving his left hand to a friend [...] your friendship, old shakebag, is all over the left as ususal.
[UK]P. Larkin letter 15 Jan. in Thwaite Sel. Letters (1992) 113: John Heath-Stubbs is reading some of my poems at a meeting of shagbags in London next Friday.
[UK]K. Amis letter 4 Oct. in Leader (2000) 294: C is a fearful shagbag.

2. attrib. use of sense 1.

[UK]‘Jon Bee’ Dict. of the Turf, the Ring, the Chase, etc. 157: ‘A shake-bag fellow,’ if he be no pick-pocket, is at least a seedy cove.