1911 Encyclopædia Britannica/Humbug
HUMBUG, an imposture, sham, fraud. The word seems to have been originally applied to a trick or hoax, and appears as a slang term about 1750. According to the New English Dictionary, Ferdinando Killigrew’s The Universal Jester, which contains the word in its sub-title “a choice collection of many conceits ... bonmots and humbugs,” was published in 1754, not, as is often stated, in 1735–1740. The principal passage in reference to the introduction of the word occurs in The Student, 1750–1751, ii. 41, where it is called “a word very much in vogue with the people of taste and fashion.” The origin appears to have been unknown at that date. Skeat connects it (Etym. Dict. 1898) with “hum,” to murmur applause, hence flatter, trick, cajole, and “bug,” bogey, spectre, the word thus meaning a false alarm. Many fanciful conjectures have been made, e.g. from Irish uim-bog, soft copper, worthless as opposed to sterling money; from “Hamburg,” as the centre from which false coins came into England during the Napoleonic wars; and from the Italian uomo bugiardo, lying man.