Note: in AM, use 'slave labor'
1.
Slave labour refers to slaves or to work done by slaves.
The children were used as ~ in gold mines in the jungle...
N-UNCOUNT
2.
If people work very hard for long hours for very little money, you can refer to it as ~.
He’s been forced into ~ at burger bars to earn a bit of cash.
N-UNCOUNT disapproval