"sleight of hand" vs. "slight of hand"

What's the magic word in this phrase? It's sleight!

Sleight is an Old Norse word meaning "cunning, crafty, or wily." It comes from the same root as sly. These days, it's almost exclusively found in the phrase sleight of hand, which refers to the way magicians or other tricksters use manual dexterity to fool their audiences. The first example sentence shows this usage; the second shows how sleight of hand can be used to evoke the same idea of trickery or misdirection in other contexts:

He'd never lost his love for sleight of hand, and he graduated from palming coins to cards, cups, wallets, and watches. (Six of Crows)

They then pulled off a fiscal sleight of hand, delaying $1.7 billion in scheduled Medicaid payments by three days — effectively pushing the cost to the following year's budget. (New York Times)

The word slight also has Scandinavian origins, but it has two distinctly different meanings. As a verb, it means "to disregard someone" — to ignore them because you don't respect or care about them. An instance of this kind of snubbing can also be called a slight. As an adjective, slight means "thin, slender, or slim." If you say that someone is "slight of hand," you might mean that she has thin, delicate hands — but you wouldn't be conveying anything about her ability to perform magic tricks.

The similarities between sleight and slight in spelling and sound — as well as the fact that sleight is not a common English word — make it easy to see how people confuse this expression, as in the examples below:

But magicians do what they do by slight of hand, and smoke and mirrors. (New York Times)

And by 1686, some inventive Scottish speakers had combined the words in the phrase joukery-pawkery, which they used to refer to clever trickery or slight of hand. (Time)

Once you know the meanings of slight, you can see that neither sentence makes sense. The hands in question are neither dismissive nor dainty. Conveniently, sleight only has one meaning, so it's easy to remember: clever, quick, and tricky like a magician's hands.