anabaptist, n. — Green’s Dictionary of Slang

anabaptist n.

[pun on SE Anabaptist, an early 16C German Protestant sect, typified by the re-baptism of all members; ult. f. Gk anabaptismos, baptize over again]

a pickpocket who had been caught in the act and ‘baptized’ by being placed beneath a pump or dumped into a pond.

1785, 1788, 1796		Grose Classical Dict. of the Vulgar Tongue.
1811		Lex. Balatronicum.