diehards vs proletariat

diehards

proletariat

noun
  • Wage earners collectively, excluding salaried workers; people who own no capital and depend on their labour for survival; the working class, especially when seen as engaged in a class struggle with the bourgeoisie (“the capital-owning class”). 

  • The lowest class of society; also, the lower classes of society generally; the masses. 

  • The lowest class of citizens, who had no property and few rights, and were regarded as contributing only their offspring to the state. 

How often have the words diehards and proletariat occurred in a corpus of books? (source: Google Ngram Viewer )