farb

(US) A historical reenactor (especially an American 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".

(US, slang, intransitive) To act like a farb; to portray a historical character in an inauthentic way.