Mephisto

1590s, Mephastophilus, the name of the evil spirit to whom Faust sold his soul in the old legend, from German (1587), a word of unknown origin. The older, Greek-like form is apparently a folk-etymology. According to the speculation of eminent Göthe scholar K.J. Schröer (1886) it is a compound of Hebrew mephitz "destroyer" + tophel "liar" (short for tophel sheqer, literally "falsehood plasterer;" see Job xiii.4). Klein writes that the names of devils in the Middle Ages "are in most cases derived from Hebrew." Related: Mephistophelian.