noun

• (communism) An advocate of a society based on the common ownership of property; a proponent of communism.
• (nonstandard) Any revolutionary or subversive radical.

noun

• (inexact) Any citizen of a country controlled by such a party, particularly Red Chinese and (historical) Soviets.
  "I caught a glimpse of them through the half-opened door, and had a passing impression of prosperous and intelligent men, with astrakhan collars to their coats, glistening top-hats, and every appearance of that bourgeois well-being which the successful Communist so readily assumes."
• (inexact, sometimes proscribed) Alternative letter-case form of communist, a proponent of the general philosophy of communism.

adj

• (inexact, sometimes proscribed) Alternative letter-case form of communist, of or related to the general philosophy of communism.
• (inexact, sometimes proscribed) Alternative letter-case form of communistic, embodying the ideals of communism.