"Pneumonoultramicroscopicsilicovolcanoconiosis" is sometimes referred to as the longest English word. It now seems that this word was invented by the National Puzzlers' League as a hoax since the first instance of it ever appearing in print is in a 1935 newspaper article:
Pneumonoultramicroscopicsilicovolcanokoniosis succeeded electrophotomicrographically as the longest word in the English language recognized by the National Puzzlers' League at the opening session of the organization's 103d semi-annual meeting held yesterday at the Hotel New Yorker. The puzzlers explained that the forty-five-letter word is the name of a special form of silicosis caused by ultra-microscopic particles of silica volcanic dust...
A book called Wordplay: A Curious Dictionary of Language Oddities tells the rest of the story:
Frank Scully, author of a series of puzzle books and later one of the early UFO enthusiasts, read the newspaper article and repeated the word in Bedside Manna: The Third Fun in Bed Book (Simon and Schuster, 1936, p. 87). On the strength of this citation, League members (with a wink from the editors?) got the word into both the OED Supplement and Webster's Third. There it remains even to this day.Whether it really counts as a word or not is moot since it would require 6 C tiles which is 3 more than are in a Bananagrams set. (See this post for a table of the letters in a Bananagrams set.)
"Supercalifragilisticexpialidocious" is a nonsense word from a song in the 1964 Disney movie Mary Poppins. In the movie, it is defined as a word to say when you don't know what to say. It is listed in some dictionaries, but only as a proper noun (i.e., the name of the song).
"Pseudopseudohypoparathyroidism" is an unusual word because of the double "pseudo". It looks like a double negative, but it's really not. Pseudopseudohypoparathyroidism is so called because it seems like pseudohypoparathyroidism in that both are disorders resulting in symptoms such as inadequate skeletal growth and shortness, but pseudohypoparathyroidism is caused by resistance to calcium and phosphorus, while pseudopseudohypoparathyroidism is not. Regular hypoparathyroidism is caused by malfunction of the parathyroid glands resulting in low levels of parathyroid hormone and as a consequence, low levels of calcium and phosphorus in the blood. It's a real word, if a highly technical one. However, the word "pseudopseudohypoparathyroidism" requires more P tiles than we have.
Which brings us to the frivolous little word "floccinaucinihilipilification". It appears to have been coined in the 18th century by Eton College students who combined a bunch of Latin roots, each meaning "nothing" or "insignificant". Floccinaucinihilipilification was defined to be the act of judging something to be worthless. (This is a typical example of 18th century college student hijinks, right up there with herding cows into campus libraries and taking apart the dean's mini-steamboat then reassembling it in someone's dorm room.) It's kind of a beautiful word. Too bad we are one C short of being able to spell it.
And so finally we arrive at "antidisestablishmentarianism", the long word you've all been waiting for. During the 19th century, the issue of whether the Church of England should be the the state church of Britain was a contentious one. The movement favoring disestablishment of the state church was referred to as "disestablishmentarianism", and the counter-movement was called "antidisestablishmentarianism". It can actually be spelled with one set of Bananagrams tiles, is generally recognized as a real word, and is therefore (by my estimate) the longest possible word in a Bananagrams game.
Words like "antidisestablishmentarianism" are agglutinative constructions. English allows such limited use of such constructions, like when combining Latin roots to form words. Forming words (even new words) by agglutinative combination is so common in the German language that there effectively is no longest German word. And in fully agglutinative languages like Turkish, extra word parts can be added on to a base word to a much greater extent. Whereas in German, nouns are routinely extended into much larger nouns, in an agglutinative language, entire sentences can be built up from one long, space-free string of letters. Word games must be very different in Turkey!
So there you have it. A tour of the forces that push words beyond their normal lengths: hoaxes, pranks, politics, medical jargon, and musicals.
I will leave you with some really long words:
and, of course,