The proletariat is that class of society whose means of livelihood entirely depend on the sale of its labor and not on the profit derived from capital; whose weal and woe, whose life and death, whose whole existence depend on the demand for labor, hence on the alternation of good times and bad, on the vagaries of unbridled competition. The proletariat, or class of proletarians, is, in a word, the working class of the 19th century.
Marx : Proletariat definition
