Longest word in English

The identity of the longest word in English depends 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
Methionylthreonylthreonylglutaminylarginyl...isoleucine	189,819	Chemical name of titin, the largest known protein	Technical; not in dictionary; disputed whether it is a word
Lopadotemachoselachogaleokranioleipsano...pterygon	183	Longest word coined by a major author,[1] considered the longest word ever to appear in literature.[2]	Coined; not in dictionary;Ancient Greektransliteration
Pneumonoultramicroscopicsilicovolcanoconiosis	45	Longest word in a major dictionary[3]	Technical; coined to be the longest word
Hippopotomonstrosesquipedaliophobia	35	Non-technical; extended fromhippopotomonstrosesquipedalian; means the fear of long words
Supercalifragilisticexpialidocious	34	Famous for being created for theMary Poppins film and musical	Coined
Pseudopseudohypoparathyroidism	30	Longest non-coined word in a major dictionary[4]	Technical
Hippopotomonstrosesquipedalian	30	Non-technical; meaning a word coined so as to be very long	Coined
Floccinaucinihilipilification	29	Longest unchallenged nontechnical word	Coined
Antidisestablishmentarianism	28	Longest non-coined and nontechnical word
Honorificabilitudinitatibus	27	Longest word in Shakespeare's works; longest word in the English language featuring alternating consonants and vowels.[5]	Latin