Wiktionary
n. 1 A person who puts slaves to work. 2 (context slang English)a person who demands excessive amounts of work from employees.
Usage examples of "slave-driver".
He specified that none of them should ever have worked within twenty miles of Tippecanoe or have any relatives there, that they should be on the train by eight next morning, and that they should be confidentially informed that the new Tippecanoe manager was a regular damnyankee slave-driver and they would better not take the job if they expected to loaf.
At home in his own island, he labours himself like a slave, and makes his people labour like a slave-driver.
Public opinion is, indeed, an unfailing restraint upon the cruelty and barbarity of masters, overseers, and slave-drivers, whenever and wherever it can reach them.