from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. A historical reenactor (especially a US civil war reenactor) whose efforts at a historically accurate portrayal are, in the opinion of the speaker, inadequate. (For example, wearing a modern wristwatch with period costume.) The opposite of farb is "hard-core" (or hardcore), someone who is, in the opinion of the speaker, an "authenticity fanatic".
Various explanations of the origin are given: (Wiktionary)