This is an American slang word of that dates to the late 19th century. It probably comes from fawney, a slang term of earlier vintage, which in turn is from the Irish fáine, or ring. Fawney also lent its name to a confidence game, referred to as the fawney rig or going on the fawney. From George Parker’s 1781 A View of Society and Manners in High and Low Life:
There is a large shop in London where these kind of rings are sold, for the purpose of going on the Fawney.
And Grose’s 1796 Classical Dictionary of the Vulgar Tongue defines the fawney rig thusly:
FAWNEY RIG. A common fraud, thus practised: A fellow drops a brass ring, double gilt, which he picks up before the party meant to be cheated, and to whom he disposes of it for less than it is supposed, and ten times more than its real value.
The phoney spelling appears on the other side of the Atlantic a century later in the 17 November 1894 Decatur, Illinois Review:
The only occasion on which we redeemed a ticket was when one of our responsible patrons was given a phony ticket by a tout.
Although there is an isolated 25 April 1862 citation in a letter from a Civil War soldier named Moody which indicates that the slang usage might date to the Civil War era. Moody writes:
They keep skirmishing along the line. I will tell you of a phoney scrape and also a serious one, too.
Here Moody seems to be using phoney to mean small or insignificant, but the sense of false or fake is not out of the question.
Other explanations of phoney are occasionally proffered. None are likely. This include the claim that it is a variation of funny or that it is somehow related to the telephone. H.L. Mencken plumped for the explanation that it is from the name Forney, a supposed manufacturer of cheap jewelry. Given that it refers to rings and jewelry, this alleged manufacturer is probably a misunderstanding of fawney.
Copyright 1997-2017, by David Wilton