hoax

The British philologist Robert Nares (1753–1829) says that the word hoax was coined in the late 18th century as a contraction of the verb hocus, which means "to cheat", "to impose upon" or "to befuddle often with drugged liquor". Hocus is a shortening of the magic incantation hocus pocus, which in turn is a contraction of the phrase Hocus pocus, tontus talontus, vade celeriter jubeo, mentioned in Thomas Ady's 1656 book A candle in the dark, or a treatise on the nature of witches and witchcraft. According to the book, the Latin-like gibberish phrase was uttered by a conjuror to distract his audience from his sleight of hand.

The term hoax is occasionally used in reference to urban legends and rumors, but the folklorist Jan Harold Brunvand argues that most of them lack evidence of deliberate creations of falsehood and are passed along in good faith by believers or as jokes, so the term should be used for only those with a probable conscious attempt to deceive.As for the closely related terms practical joke and prank, Brunvand states that although there are instances they overlap, hoax tends to indicate "relatively complex and large-scale fabrications" and includes deceptions that go beyond the merely playful and "cause material loss or harm to the victim".
P. T. Barnum's Fiji mermaid (1842)

According to Professor Lynda Walsh of the University of Nevada, Reno, some hoaxes—such as the Great Stock Exchange Fraud of 1814, labeled as a hoax by contemporary commentators—are financial in nature, and successful hoaxers—such as P. T. Barnum, whose Fiji mermaid contributed to his wealth—often acquire monetary gain or fame through their fabrications, so the distinction between hoax and fraud is not necessarily clear. Alex Boese, the creator of the Museum of Hoaxes, states that the only distinction between them is the reaction of the public, because a fraud can be classified as a hoax when its method of acquiring financial gain creates a broad public impact or captures the imagination of the masses.