Sesquipedalianism is a literary term for the extravagant use of exceedingly long words. “Sesquipedalian” literally means “words that are a foot and a half long.” It is a form of self-referential language joke, as the word “sesquipedalianism” is itself a very long word. The English language has a plethora of such multisyllabic words, most of which are used for humorous or showy effect. These include words like “antidisestablishmentarianism” that rarely, if ever, come up in casual conversation.
The phrase sesquipedalia verba was coined by the Roman humorist Horace in the 1st century BC. Horace was satirizing another writer’s habit of using long words. The Latin term sesqui means “one and a half” and ped means foot; hence, words that are a foot and a half long. Horace’s phrase was translated into English in the 1650s, according to the Oxford English Dictionary (OED), a standard reference for language usage. The OED states that the word “sesquipedalianism” was first recorded in 1863.
Some sesquipedalian words are created by the addition of multiple prefixes and suffixes to otherwise ordinary terms. This is the case with “antidisestablishmentarianism,” a term used in the conflict over state establishment of religion in Great Britain in the 19th century. The word, with 12 syllables encompassing 28 letters, is considered the longest non-scientific word in the English language. Only a few scientific terms have greater length; the most famous is pneumonoultramicroscopicsilicovolcanoconiosis, a lung disease caused by inhalation of volcanic dust. That word is far more likely to appear in discussions of sesquipedalianism than in medical treatises, however.
Word hobbyists and language professionals are the most likely users of sesquipedalian words. American writer and political activist William F. Buckley was noted for his use of vastly long words, even when writing spy novels for the popular market. In the 1930s adventures of pulp-fiction hero Doc Savage, the supporting character Johnny Littlejohn was a famous sesquipedalianist. In times of crisis, Johnny was inclined to use unlikely phrases such as “I’ll be superamalgamated!” Most sesquipedalian phrases are likewise used for humorous effect.
Like many hobbyists, language lovers are prone to try topping each other and setting new records. Thus, for word lovers who think the word “sesquipedalian” is too short, an even longer alternative exists. The word is “hyperpolysyllabicsesquipedalianism,” and it means the same thing as “sesquipedalianism;” while real, it clearly only exists to inflate sesquipedalianism to new heights of absurdity. For those who feel this is all just too much, there is the word “hippopotomonstrosesquipedaliophobia.” It means “the fear of extremely long words.”