socialist

Etymology

From social + -ist.

adj

1. Of, relating to, supporting, or advocating socialism.
   ...it must be remembered that in a Socialist farm or manufactory, each labourer would be under the eye not of one master, but of the whole community. 1848, John Stuart Mill, Principles of Political Economy, Book II, Chapter 1
   I am convinced there is only one way to eliminate these grave evils, namely through the establishment of a socialist economy, accompanied by an educational system which would be oriented toward social goals. 1949 May, Albert Einstein, “Why Socialism?”, in Monthly Review

noun

1. One who supports or advocates socialism.
   A contest, who can do most for the common good, is not the kind of competition which Socialists repudiate. 1848, John Stuart Mill, Principles of Political Economy, Book II, Chapter 1