Green’s Dictionary of Slang

rapping n.¹

perjury.

1743		Fielding Life of Jonathan Wild (1784) I 144: It was his constant maxim, that he was a pitiful fellow who would stick at a little Rapping for his friend.
1747		Life and Character of Moll King 21: There’s a great Brandy-Merchant, who was, for his much greater Skill in Rapping [...] made Overseer of the Mob in Kingston Market Place.
1857		‘Ducange Anglicus’ Vulgar Tongue.