from The American Heritage® Dictionary of the English Language, 4th Edition
- n. Slang A Communist Party sympathizer.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. A Communist sympathizer; a liberal.
Com(munist) + symp(athizer).(American Heritage® Dictionary of the English Language, Fourth Edition)
Coined by Robert Welch (1899-1985), founder of the John Birch Society. (Wiktionary)