communism

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A theoretical economic system characterized by the collective ownership of property and by the organization of labor for the common advantage of all members.
• noun A system of government in which the state plans and controls the economy and a single, often authoritarian party holds power, claiming to make progress toward a higher social order in which all goods are equally shared by the people.
• noun The Marxist-Leninist doctrine advocating revolution to overthrow the capitalist system and establish a dictatorship of the proletariat that will eventually evolve into a perfectly egalitarian and communal society.

from The Century Dictionary.

• noun An economic system, or theory, which rests upon the total or partial abolition of the right of private property, actual ownership being ascribed to the community as a whole or to the state.
• noun Communalism.

from the GNU version of the Collaborative International Dictionary of English.

• noun A scheme of equalizing the social conditions of life; specifically, a scheme which contemplates the abolition of inequalities in the possession of property, as by distributing all wealth equally to all, or by holding all wealth in common for the equal use and advantage of all.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun Any political philosophy or ideology advocating holding the production of resources collectively.
• noun Any political social system that implements a communist political philosophy.
• noun The international socialist society where classes and the state no longer exist.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun a political theory favoring collectivism in a classless society
• noun a form of socialism that abolishes private ownership