which 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.