Slave Labour

"persons, especially a large group, performing labor under duress or threats, as prisoners in a concentration camp; a labor force of slaves or slave like prisoners." - dictionary.com

Slave labour happens when a person takes a loan under the condition that they will work to pay off the loan, but it is designed that it can never be paid off. It is commonly passed down through generations of that family. They will be threatened or abused to do work..