Green’s Dictionary of Slang

a cheat, a deceiver.

1655		Mercurius Fumigosus 44 28 Mar.–4 Apr. 349: She is to be led quite through the Suburbs into St. Gyles in the Fields, where are to meet the Devills Black Guard of Pimps, Panders, Hectors, Trappaners, Bawdes, Whores, Punks, Pimping-Drawers, blind Fidlers and Hackney Coach-men.
1660		Wandring Whore II 12: I’le send her all the Hectors, and roaring Trappanners that love picking of wenches plackets more than Pockets to plague the jade.
c.1663		‘Iter Hibernicum’ in Carpenter Verse in English from Tudor & Stuart Eng. (2003) 398: Beleeving Knigjhts were no Trapanners, / But were, or should be, Man of Merrit.
1669		Nicker Nicked in Harleian Misc. II (1809) 108: There come in shoals of hectors, trepanners, gilts, pads, biters, prigs, divers.
1676		‘Cupids Trappan’ in Euing Broadside Ballads No. 35: I’ll sing and I’ll dance, and my spirits advance, / In spite of all Cupid’s Trappanners, brave boys.
1681		Dialogue Between Sam, Ferry-man etc. Upon a Parliament at Oxford in Harleian Misc. II (1809) 126: I take him to be a cross-biter*; but if he chance to be hanged, as he is like to be, it is doubtful if he will be cross-bitten himself. [*viz. a trepanner].
1700		Constables Hue and Cry 2: To all Informers, Thief catchers, Trapanners &c.
1734		C. Johnson Hist. of Highwaymen &c. 192: The former of which Planet is of a thievish, cheating, deceitful Influence; and the other hath Dominion over all Whores, Bawds, and Pimps; and, joyn’d with Mercury, over all Trepanners and Hectors.
1790		‘The Bowman Prigg’s Farewell’ in Wardroper (1995) 283: Then adieu to all kins and knots, / To kid-layers, files and trapanners.
1854		Derby Mercury 12 July 8/1: The legislative enactment for punishing the trapanners of female innocence.
1867		Wilmington Jrnl (NC) 10 May 2/3: This view alone will ensure them from being entangled in the meshes which the cunning trepanners have set for them.
1881		Clay Center Dispatch (KS) 21 July 5/2: People guessed at the meaning [...] of the two transmigratory trapanners.