Wage Slavery is when a person is forced to work for someone in order to merely subsist meaning to stay alive. Also it's when someone is earning money to completing a dependent on wages earned.
A wage earner whose livelihood is completely dependent on the wages earned.
"Together with an immense expansion of democracy which for the first time becomes democracy for the poor, democracy for the people, and not democracy for the rich folk, the dictatorship of the proletariat produces a series of restrictions of liberty in the case of the oppressors, the exploiters, the capitalists. We must crush them in order to free humanity from wage slavery; their resistance must be broken by force; it is clear that where there is suppression there is also violence, there is no liberty, no democracy.
--Vladimir Illyich Lenin. State and Revolution, 1918 Modern History Sourcebook