A Neo-Marxist is someone who, in contrast to Orthodox Marxists, reject the concept of economic determinism; the idea that all of society's decisions are ultimately determined by economic conditions, and that capitalist societies will inevitably collapse due to the capitalist economic system's inherent contradictions. Neo-Marxists believe that society's decisions are determined by ideology as well as economic conditions, and that it is the hegemonic ideology of the bourgeoisie that keeps workers from starting the world revolution that Orthodox Marxists (such as Marx, Engels, Lenin and Stalin, etc) thought was inevitable.
There is controversy over the term, as some thinkers like Noam Chomsky have been described being Neo-Marxist despite preferring to be described as anarcho-syndicalist or libertarian socialist.
While there are many branches of Neo-Marxism that are not always in agreement with eachother, the writings of Antonio Gramsci and scholars at the Frankfurt School are highly influential in Neo-Marxist thought.

A neo-marxist is a person who adheres to neo-marxism. Neo-marxism is an offshoot of marxism, in which it is believed that all societal ills come from the divide between the rich (who are claimed to be undeserving of their wealth) and the poor (who are claimed to be oppressed). Marxists believe that all personal failings are of a direct result of someone else oppressing you, and that another person cannot be successful without oppressing another.

Neo-marxism differs from marxism by abandoning the dichotomy of rich vs poor and instead adopt identity politics. Instead of the dichotomy being between wealthy and poor, it is between successful and unsuccessful demographics. Neo-marxists divide all demographics (white, black, asian, male, female, gay, straight, etc) and place them in a hierarchy of oppression as determined by how successful that demographic is. White and Asian men are at the bottom of this hierarchy, whereas blacks and females are near the top (although the exact order is not widely accepted).

Neo-marxists believe that successful demographics are only successful because they exploit the less successful demographics, and as such believe that the more successful demographics (i.e the 'rich' of classical marxism) should be punished in some way, and what they have should be given to the less successful demographics. Typically this involves giving these demographics money, positions, and political influence simply for being a member of a "oppressed" demographic.

A person who is often mistakenly accused of wanting government to control everything and hand out free shit.

A theoretical perspective of the social sciences which incorporates all the critical theories into one. Often used in essays when no mainstream theory can be made to fit the argument.