Member of the working class (5)
I believe the answer is:
prole
'member of the working class' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for prole that I've seen before include "Member of the poorest class (colloq.)" , "Marxism's member of the working class (abbr)" , "The old keep moving" , "Peasant" , "poor person" .)