Green’s Dictionary of Slang

(US) cheating, deceiving, also as adj.

1911		El Paso Herald (TX) 26 July 6/3: As a result of [...] the hornswoggling deal put over on him.
1921		Princeton union (MN) 3 Nov. 6/2: We are just wondering a bit what sort of a line of hornswoggling the republican (state) machine is figuring on hooking the democratic suckers with.
1934		H. Miller Tropic of Cancer (1963) 262: All that lip-chewing and hornswoggling just to fuirnish a little strength!