The term lumpenproletariat was coined by Karl Marx in The German Ideology in the course of a critique of Max Stirner. Stirner frequently used the term Lumpe, but never used the term “lumpenproletariat.” Lumpen originally meant “rags,” was later used to mean “a person in rags.” The term lumpenproletariat was applied to slum workers or the mob. Lumpenproletariat is a term used by Marxist theorists to describe the underclass. The term Lumpenproletariat was used originally in Marxist theory to describe those members of the proletariat who lacked awareness of their collective interest and class oppression. The term Lumpenproletariat includes the unemployed, the homeless, and career criminal. Economist Richard McGahey, writing for the New York Times in 1982, noted that it is one of the older terms used in labeling theory that attached stigma to poor people for their poverty, and listed the following synonyms: "underclass", "undeserving poor", and culture of poverty in "culture of poverty thesis".
The term Lumpenproletariat has also been rendered as "social scum", "dangerous classes", "ragamuffin", and "ragged-proletariat". Lumpenproletariat identifies the class of outcast and submerged elements that make up the population of industrial centers. Lumpenproletariat includes beggars, prostitutes, racketeers, petty criminals, tramps, persons who have been cast out by industry, and all sorts of declassed or degraded elements. In Marxist terminology the lumpenprolertariat are the dregs of humanity without interest in attaining class consciousness. Lumpenproletariat also came to mean “riff-raff” or “knave.”
Lumpenproletariat was later to be used freely as a prefix to perjorative terms. Lumpenproletariat used to be a word that was frequently used when people took the Communist Party seriously. In times of depression many people are pushed into this limbo of lumpenproletariat. In the view of Karl Marx and Friedrich Engels, the lumpenproletariat consists of people who subsist on the margins of society and scavenge a living.