flim·flam

Pronunciation:
\ˈflim-ˌflam\

Function:
noun

Etymology:
perhaps of Scandinavian origin; akin to Old Norse flim mockery

Date:
circa 1570

1 : deceptive nonsense

2 : deception , fraud

(Via Definition from the Merriam-Webster Online Dictionary.)

From Wikipedia: A confidence trick or confidence game (also known as a bunko, con, flim flam, gaffle, grift, hustle, scam, scheme, or swindle) is an attempt to defraud a person or group by gaining their confidence.

The first known usage of the term "confidence man" in English was in 1849; it was used by American press during the United States trial of William Thompson. Thompson chatted with strangers until he asked if they had the confidence to lend him their watches, whereupon he would walk off with the watch; he was captured when a victim recognized him on the street.[1]

The term 'scam' is often used to describe the 'confidence trick' employed by a 'confidence man'. The origin of this word is thought to come from the Irish phrase 'S cam é (pron. s'cam ae) meaning 'it is a trick' [2]