Deception.
“Doubtless the pleasure is as great
Of being chented as to cheat;
As lookers-on feel most delight
That least perceive a juggler’s sleight,
And still the less they understand,
The more they admire his sleight of hand.”
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Entry taken from Dictionary of Phrase and Fable, edited by the Rev. E. Cobham Brewer, LL.D. and revised in 1895.