1. Some claim that the longest English word is:
2.The longest word in any of the major English language dictionaries is pneumonoultramicroscopicsilicovolcanoconiosis", a word that refers to a lung disease contracted from the inhalation of very fine silica particles, specifically from a volcano; medically, it is the same as silicosis
3.The longest Welsh word is: "Llanfairpwllgwyngyllgogerychwyrndrobwllllantysiliogogogoch" (lan-vire-pool-guin-gith-go-ger-u-queern-drob-ooth-clandus-ilio-gogo-goch) is a Welsh word which translates roughly as "St Mary's Church in the Hollow of the White Hazel near a Rapid Whirlpool and the Church of St. Tysilio near the Red Cave.
4. The longest Bengali words are:" অঘটনঘটনপটিয়সী, কিংকর্তব্যবিমূঢ়, নিশীথবনভ্রমণবিলাসিনী"
5.The Guinness World Record for the longest word used in any language in the world literature is a Sanskrit compound word composed of 195 Sanskrit characters. This transliterates into more than 400 letters in the roman alphabets used by the English language