The longest word is a chemical name, the 189,819 letter technical term for the protein "titin" (it will not display here - see the related link).
Other long words in English are
-- "pneumonoultramicroscopic-silicovolcanoconiosis"
(no hyphen), a 45-letter coined term for volcanic dust silicosis of the lungs
-- "floccinaucinihilipilification"
(no hyphen) a 29-letter word coined at Eton to suggest regarding something as worthless or insignificant
-- "antidisestablishmentarianism"
the opposition to disestablishing a church as an official religion.
(commonly regarded as the longest actual word in English dictionaries)
There are also very long words possible in Finnish, Hungarian, and Greek.
(see the related question below)
It depends which word you are counting as the longest.
there are approximately 193 words
1909
1,909 letters in the longest word
Antidisestablishmentarianism is the longest non-technical word with 28 letters
Methionylthreonylthreonylglutaminylalanyl...isoleucine. It has 189819 letters and the longest word in the world.
1909
One can find the longest word in the dictionary, to be more specific, the Merriam-Webster online, the word has letters but still not the longest word in the world.
The world's longest word, which is the chemical name for titin, has 189,819 letters and 189,819 syllables. It would take over 3 hours to say the entire word out loud.
One very long word that starts with m is: microcryptocrystalline (22 letters)
The longest word in the English language, "pneumonoultramicroscopicsilicovolcanoconiosis," has 12 syllables.
Aegilops is the longest word whose letters are in alphabetical order.
5 is the longest word I found "VIDEO"
There is no English word that uses all 7 of these letters. The longest word using these letters in unreel. The longest word using the j is jurel.