Underclass

A class of individuals situated right at the bottom of the class system, often composed of people from ethnic minority backgrounds.
Found on http://www.encyclo.co.uk/local/20212

underclass

a disputed concept implying that there is a class of the population with distinctive cultural traits who are dependent on state benefits and/or poorly paid and are therefore locked into disadvantaged circumstances.
Found on http://www.polity.co.uk/cbs3/PDF/Glos.pdf

Underclass

a group 'under the class structure' which is economically, politically and socially marginalised and excluded
Found on http://wps.pearsoned.co.uk/wps/media/objects/2143/2195136/glossary/glossary

underclass

(from the article `social class`) ...a core of chronically unemployed persons isolated from the economic mainstream in decaying urban areas. This new urban substratum of permanently ...
Found on http://www.britannica.com/eb/a-z/u/7
No exact match found