slaving
n.— «The director of the Workplace Centre at the University of Sydney, Dr John Buchanan, says the practice of employees receiving low wages in return for expensive training is referred to as “slaving,” and he says it is endemic in the Queensland dive industry.» —“Legal loophole allows ‘slaving’ of young workers” by Conor Duffy, Michael Edwards ABC News (Australia) Aug. 3, 2007. (source: Double-Tongued Dictionary)