Synonyms for Proletarian (same or very similar meaning)
WordNet sense 1 (a member of the working class (not necessarily employed)):
worker, prole
WordNet sense 2 (the lowest class of citizens of ancient Rome who had no property):
propertyless
WordNet sense 3 (occupying the lowest socioeconomic position in a society):
lower-class, low-class
From the ODE community, based on WordNet
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