The Oxford English Dictionary describes it as "of obscure origin", possibly deriving from a historical sense of "shy" meaning disreputable.
A book published in 2013 traces the first use back to 1843, when scammers in New York City would exploit prisoners by pretending to be lawyers.
These scammers were disparagingly referred to as "shisers", meaning "worthless people" in British slang, which in turn was originally derived from the German "Scheißer".
[3] Various etymologies have suggested an antisemitic origin, possibly associated with the character of Shylock from Shakespeare's The Merchant of Venice, but there is no clear evidence for this.
[6][7] When contacted by the ASA, the Board of Deputies of British Jews stated that they did not have concerns with the advertisement's content.