/bamf/ 1. [Old X-Men comicS] Notional Sound made by a perSon or object teleporting in or out of the hearer' S vicinity. Often uSed in virtual reality (eSpecially MUD) electronic fora when a character wiSheS to make a dramatic entrance or exit. 2. The Sound of magical tranSformation, uSed in virtual reality fora. [Jargon File]