from The American Heritage® Dictionary of the English Language, 4th Edition
- n. One that supports a cause, especially vehemently.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. One who beats a drum.
- n. A propagandist.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. a fervent and even militant proponent of something
drum + beater (Wiktionary)