Definition of "shylock"

Eventually, their gambling debts grow so big that they are cut off from making any more bets, eliminating the chance that they can make enough money to satisfy their shylocks.

2005, Joe Pistone, The Way of the Wiseguy‎, page 45

If a guy got into hock with several shylocks from different crews and was unable to keep up with his weekly payments, a sit-down would have to be called with all of the shylocks involved and their respective capos.

2009, G. T. Harrell, For Members Only: The Story of the Mob's Secret Judge, A True Story‎, page 229

After Caspian's father killed his credit lines at all the big casinos, he ran up a six-figure tab with a couple of shylocks in Miami, then couldn't make the vig.

2013, James Lee Burke, Light of the World‎, page 429

I wanted to know whether shylocking is a legal business or not, and if it is legal, under which Act does it operate?

2004 December 8, Kenya National Assembly Official Record (Hansard), page 4928

When you've accumulated a good stash of money, you may want to go into the nightclub business, or shylocking. Shylocking is free. There is no ten percent vig on loan sharking.

2005, Tom Layne, The Assassination of Rush Limbaugh, page 151

Lori said it sounded outright felonious, but Dad said all he was doing was outsmarting the fat-cat bank owners who shylocked the common man by charging usurious interest rates.

2005, Jeannette Walls, The Glass Castle‎, published 2010

Do you recall this question having been put to you—the shylocking business you were involved in continued right up until the time that you were arrested, correct?

2011, John Nicholas Iannuzzi, Handbook of Cross Examination: The Mosaic Art‎, 3rd edition, page 312