The slang use of the term "Shylock" originated from Shakespeare's money-lending character in the Merchant of Venice.

When the all-Sicilian "Black Hand" was finally suppressed in NYC by the NYPD at the fin-de-siecle --
Ernest Borgnine portrayed an Italian NYPD officer battling the "Black Hand" in Pay or Die! (1960) -- the Italian mafia began to absorb other ethnic gangs into their midst to make money together.

Also recall The Godfather scene when the mustachioed man in the white suit is plugged on the street with a revolver by the young Don Corleone. The victim was a leader of the "Black Hand."

The first non-Sicialians to cooperate with the mafia in the US were the organized Jewish gangs -- e.g. Meyer Lansky and Bugsy Siegel -- and the Purple Gang in Detroit -- followed later by the unruly Irish gangs which required more "convincing" (the "Westies" -- see State of Grace (1990) starring Sean Penn.)

African-American organized crime also cooperated with the mafia in the Bronx and Harlem -- something which led to the 24 Oct 1935 demise of Dutch Schultz (this week 91 years ago). An excellent film and cult classic about organized crime in Harlem is Across 110th Street (1972) starring Yaphet Kotto.

Uneducated Italians in the mafia were introduced to Yiddish terms when the cooperative era started.

The "Vig" derives from the Yiddish word viggorish -- the usurious interest rate forced on borrowers.

The slang term Shylock -- which evolved into an antisemitic trope over the centuries -- was used by the mafia to describe loansharks of any ethnic origin and was most likely introduced into their vernacular by either the Jewish or Irish gangsters who were slightly or more educated than their Sicilian counterparts.

When Dumpkopf Trumpf uses the word "Shylock," he is merely using the word he is accustomed to in NYC when he dealt with mafioso in the 1980s like Sammy "the Bull" Gravano and others. His racist father probably used that term also. Trumpf has no idea the word came from Shakespeare or that for many outside NYC this has an antisemitic connotation.

I used the term "Shylock" a few times in official reporting, alternating that word with loanshark, so as not to be repetetive in my writing and my supervisors did not diapprove.

Coda: American and English writers such as A. Conan Doyle, Ernest Hemingway, Jack London, Agatha Christie, Charles Dickens, and F. Scott Fiztgerald used subtle or overt language to ensure the reader knew the character was Jewish: e.g. "Hook-nosed" or "beady eyed." Everyone knew that the "Napoleon of Crime" -- by narrative description -- Professor Moriarty -- was Jewish. This was a needless aspersion, as in the case of Fagin in Oliver Twist.

What would it matter if Lex Luthor or the Joker were Jewish or Arabic?

When the comic book The Fantastic Four debuted in 1962, everyone knew that test pilot Ben Grimm -- who would become the orange rocky golem super-strong The Thing -- was Jewish. This was implicit by Stan Lee and Jack Kirby. Back then, the Comics Code prevented overt identification of one's religious denomination.

Ernest Hemingway wrote that the best thing to have ever happened to a Jewish protagonist -- a skilled pugilist from Princeton University -- was to have "his nose flattened" (The Sun Also Rises, 1926).

Shakespeare did not disparage the money-lender Shylock any further than he had to -- just as he treated England's eternal enemy -- the Irish. He ridiculed the Irish just enough during a late 17th-century insurrection just to please the London audience -- but no more. (Nota Bene: Jews were expelled from England in 1290 and were finally allowed to return to Old Albion in 1656 under authoritarian Oliver Cromwell, years after the Bard of Avon's short life (23 April 1564 - 23 April 1616).

To his immortal credit, New York City writer Damyon Runyan did not disparage other ethnicities or races in his canon of work. When Runyan wrote stories which included the character "Big Nig," everyone realized the colorful individual was an "HBM" (huge black male). But this was not a slur on "Big Nig" and his character was not maligned. This "HBM" was accepted in the mostly white and rowdy Broadway crowd, part of Gotham's tapestry, just like Nicely-Nicely or Sky Masterson.