Green’s Dictionary of Slang

sneaksby n.

[sneak v. (2)]

a term of general disparagement.

[UK]Urquhart (trans.) Gargantua and Pantagruel (1927) I Bk I 103: The bunsellers or cake-makers [...] did injure them most outrageously, calling them [...] staring clowns, forlorn snakes, ninny lobcocks, scurvy sneaksbies, fondling fops, base loons, saucy coxcombs, idle lusks, scoffing braggards, noddy meacocks, blockish grutnols, doddi-pol jolt-heads.
[UK]Grose Classical Dict. of the Vulgar Tongue (3rd edn) n.p.: Sneaksby. A mean-spirited fellow, a sneaking cur.
J.K. Paulding in Liverpool Mercury 28 May 3/4: The tenants, who for several years had been calling him a poltroon, and a sneaksby, for putting up with Squire Bull’s insults.
[UK]Egan Grose’s Classical Dict. of the Vulgar Tongue.
[UK]letter in Worcs. Chron. 1 May 4/4: [H]aving conquered the right of free election from authority, we should be great Sneaksbys to give it up to those without any authority.
Bystander (London) 3 Aug. 172/2: Light-minded sneaksbies are always trying to catch Auntie napping.