To SNAFFLE,
to steal, to rob, to purloin. A snaffler of Prancers; a Horse-Stealer. Snuffle, is also a Highwayman that has got a Booty.
· 
· 
Entry taken from 1736 Canting Dictionary, by Nathan Bailey.
To Snaffle in the 1811 Vulgar Tongue
Also see examples in Canting Songs and Slang Rhymes collected by John S. Farmer (1896).