The Longest Words In The English Language sesquipedalianism Let’s start off with a word related to the business of “longest words.” Sesquipedalianism is the tendency to use long words. Do you have sesquipedalian tendencies? (We do.) The word is traced to the ancient Roman poet Horace, who in a treatise on the art of poetry, wrote that in certain circumstances, poets must avoid sesquipedalia verba, a Latin phrase meaning “words [verba] a foot and a half long [sesquipedalia].” Horace clearly had a sense of humor. WATCH: We Asked These People What Words They Always Say Wrong ... Previous Next pneumonoultramicroscopicsilicovolcanoconiosis There are a number of very long words in the medical and science fields, and one that has our jaw on the floor is pneumonoultramicroscopicsilicovolcanoconiosis (that’s 45 characters). This word—apparently invented in 1935 to be deliberately long in mockery of long medical words—is the name of an occupational lung disease resulting from inhaling crystalline silica dust (pneumoconiosis). pseudopseudohypoparathyroidism We include pseudopseudohypoparathyroidism, another medical science term, because this one is considered the longest non-fabricated word to appear in major dictionaries. Pseudo- is a combining form meaning "false, pretended, unreal." You might notice the appearance of pseudo- twice. That’s because this disorder simulates the symptoms of pseudohypoparathyroidism, in which the body doesn't respond to the parathyroid hormone. So, there are two levels of "faking it" going on here. antidisestablishmentarianism Antidisestablishmentarianism is a prime example of a sesquipedalian word. The word isn’t really used today and never really was ... except in reference to very long words, like here. The word pertains to the 19th-century opposition to (anti-) the dismantling of the Anglican Church’s place as the state church of England, Ireland, and Wales (disestablishment). floccinaucinihilipilification Here’s one that is also very meta: floccinaucinihilipilification is a rarely used word that means "the estimation of something as valueless." It is usually used in reference to itself! Dating back to the 1700s, the word contains four Latin roots that all mean “of little value” or “trifling”: flocci, nauci, nihili, and pili. incomprehensibilities At 21 characters, one of the longest words you might actually use yourself is incomprehensibilities. We define incomprehensible as “impossible to comprehend or understand,” so incomprehensibilities are "things you can't comprehend." Comprende? uncopyrightables If you look closely at the spelling, you’ll notice a peculiar thing about this word with 16 letters. It does not repeat any letter; each character is used only once. This word is sometimes called an isogram among lovers of words and word games. One of the longest isograms is subdermatoglyphic, at 17 characters. But, since subdermatoglyphic (dermatoglyphics studies the patterns of skin markings on the hands and feet) is a bit scientific and certainly not one that is used often, we’re spotlighting uncopyrightables instead, because it's one we can all remember. It means, of course, "items that are unable to be copyrighted." squirrelled We appreciate the uniqueness of this word. Most English dictionaries accept this spelling (usually one L in American English), which makes squirrelled ("having hidden something of value away in a safe place") one of the longest words pronounced in one syllable. It’s like squirrelling away your syllables for a rainy day. uncharacteristically There are a few words in the 20-plus-letter range that are not scientific or coined to be long, but they exist: counterrevolutionaries and deinstitutionalization, to name two. One actually common one is uncharacteristically, which means "in the manner of something that is not typical of a particular person or thing." Uncharacteristically, as far as long words go, is uncharacteristically common. PricewaterhouseCoopers This is that company that, among many other things, tallies the votes at the Academy Awards, including notoriously botching the Best Picture announcement in 2017. PricewaterhouseCoopers really does officially spell their name like that, clocking in at 22 characters. That's probably why they do business as the much shorter Pwc. dichlorodiphenyltrichloroethane This is the longest word (well, item) banned by the government: dichlorodiphenyltrichloroethane, or as it’s known by the easier-to-pronounce abbreviation, DDT. Agricultural use of the chemical was banned back in 1972. Chargoggagoggmanchauggagoggchaubunagungamaugg Take a dip into Lake Chargoggagoggmanchauggagoggchaubunagungamaugg. Seriously. That’s 58 characters, and is thought to be the longest placename in the US. Located in Webster, Massachusetts, it also answers to ... Webster Lake. That doesn't have the same ring to it, though. abstentious This 11-letter word, abstentious, is considered the longest word that features the vowels in alphabetic order exactly (A-E-I-O-U). Sorry, Y. Related to the word abstain, abstentious can characterize someone who doesn't indulge in excesses. supercalifragilisticexpialidocious We thought we’d end with a word that might evoke a happy childhood memory. If you've seen the 1964 movie Mary Poppins, you might remember singing along to the song, “Supercalifragilisticexpialidocious." While Mary Poppins popularized this word you say when you don't know what else to say, the nonsensical supercalifragilisticexpialidocious can be found in various versions as early as the 1930s, including in a 1949 song whose songwriters tried (and failed) to sue Disney for copyright infringement. Speaking of uncopyrightables ... Phew! This slideshow was a mouthful!