1841, as both a noun and adjective, from French communiste, from commun (Old French comun "common, general, free, open, public;" see common (adj.)) + -iste (see -ist). First attested in writing by John Goodwin Barmby (1820-1881), British Owenite and utopian socialist who founded the London Communist Propaganda Society in 1841. Main modern sense, "an opponent of capitalism or supporter of revolutionary leftism," emerged after publication of Communist Manifesto ("Manifest der Kommunistischen Partei") in 1848.

All communists without exception propose that the people as a whole, or some particular division of the people, as a village or commune, should own all the means of production--land, houses, factories, railroads, canals, etc.; that production should be carried on in common; and that officers, selected in one way or another, should distribute among the inhabitants the fruits of their labor. [Richard T. Ely, "French and German Socialism in Modern Times," New York, 1883] 

 Shortened form Commie is attested from 1939. Century Dictionary (1900) recognizes the noun alone; as an adjective it has only communistic (1850) "relating to communists or communism." 

Definitions of communist
communist (n.)
a socialist who advocates communism;
Synonyms: commie
communist (adj.)
relating to or marked by communism;
communist governments
Synonyms: communistic
Communist (n.)
a member of the communist party;