/lum"peuhn proh'li tair"ee euht/ , n. ( sometimes cap. ) (esp. in Marxist theory)
the lowest level of the proletariat comprising unskilled workers, vagrants, and criminals and characterized by a lack of class identification and solidarity.
[ 1920-25; Lumpen rag or Lumpen-, comb. form of Lump ragamuffin + Proletariat PROLETARIAT ]