legerdemain

In Middle French, folks who were clever enough to fool others with fast-fingered illusions were described as "leger de main," literally "light of hand." English speakers condensed that phrase into a noun when they borrowed it in the 15th century and began using it as an alternative to the older "sleight of hand." (That term for dexterity or skill in using one's hands makes use of "sleight," an old word from Middle English that derives from an Old Norse word meaning "sly.") In more modern times, a feat of legerdemain can even be accomplished without using your hands, as in, for example "an impressive bit of financial legerdemain."