Longest word

The identity of the longest word in Englishdepends upon the definition of what constitutes a word in the English language, as well as how length should be compared. In addition to words derived naturally from the language's roots (without any known intentional invention), English allows new words to be formed by coinage and construction; place names may be considered words; technical terms may be arbitrarily long. Length may be understood in terms of orthography and number of written letters, or (less commonly) phonology and the number of phonemes.

Word	Letters	Characteristics	Dispute
Methionylthreonylthreonylglutaminylalanyl...isoleucine	189,819	Chemical name of titin, the largest known protein	Technical; not in dictionary; disputed whether it is a word
Methionylglutaminylarginyltyrosylglutamyl...serine	1,909	Longest published word[1]	Technical
Lopadotemachoselachogaleokranioleipsano...pterygon	182	Longest word coined by a major author,[2]the longest word ever to appear in literature[3]	Coined; not in dictionary; Ancient Greektransliteration
Pneumonoultramicroscopicsilicovolcanoconiosis	45	Longest word in a major dictionary[4]	Technical; coined to be the longest word
Supercalifragilisticexpialidocious	34	Made popular in the Mary Poppins filmand musical	Coined
Pseudopseudohypoparathyroidism	30	Longest non-coined word in a major dictionary[5]	Technical
Floccinaucinihilipilification	29	Longest unchallenged nontechnical word	Coined
Antidisestablishmentarianism	28	Longest non-coined and nontechnical word[6]
Honorificabilitudinitatibus	27	Longest word in Shakespeare's works; longest word in the English language featuring alternating consonants and vowels[7]	Latin