Hocus-pocus is a noun used to describe magic or sleight of hand, often in a derogatory sense (as in ‘the saleperson did some kind of hocus-pocus and now I own a cow’). But did you know that actually, using it might get you struck by lightning/sent straight to hell (if you believe in that type of thing, of course)? That’s because some people believe it’s a corruption (or a perversion if you’re feeling particulary angry) of the phrase ‘Hoc est enim corpus meum’ or ‘This is my body’ which is used in Catholic masses for the Eucharist. GASP. This connection was first made in 1694 (which shows how old the word is) by John Tillotson, who was only the bloody Archbishop of Canterbury. He said this is one of his sermons:
“In all probability those common juggling words of hocus pocus are nothing else but a corruption of hoc est corpus, by way of ridiculous imitation of the priests of the Church of Rome in their trick of Transubstantiation.”
Despite this, there isn’t any real evidence to prove that 17th-century conjurers were actively trying to commit blasphemy or sentence themselves to eternal damnation. It’s more likely that hocus-pocus is just a couple of rhyming nonsense words put together that magicians incorporated into their patter to help them misdirect their audiences.
There’s also a theory that we get the word ‘hoax’ from the ‘hocus’ of ‘hocus pocus’, which was itself used on its own to mean ‘to play a trick on, to trick (someone)’ or, randomly, ‘to stupefy (someone) with drugged liquor ( … to steal from them)’ (from Wiktionary).