(3 syl.). One of the rabble. Prolétaires in French means the lowest and poorest class in the community. Proletarian, mean or vulgar. The sixth class of Servius Tullius consisted of proletarii and the capite censi —i.e. breeders and human heads. The proletaries could not enter the army, but were useful as breeders of the race (proles). The capite censi were not enrolled in the census by the value of their estates, but simply by their polls.
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894