Source: Merriam-Webster dictionary
Definition 1: any of various economic and political theories advocating collective or governmental ownership and administration of the means of production and distribution of goods
Definition 2 a: a system of society or group living in which there is no private property, Definition 2 b: a system or condition of society in which the means of production are owned and controlled by the state
Definition 3: a stage of society in Marxist theory transitional between capitalism and communism and distinguished by unequal distribution of goods and pay according to work done