What is the longest word in English ?

The longest word is actually isoleucine (for short). It is the name of 'titin', the largest known protein in the human body. The word has 189,819 characters.

Here's the link: https://www.digitalspy.com/fun/a444700/longest-word-has-189819-letters-takes-three-hours-to-pronounce/

Explanation:

But it isn't in the dictionary. The longest word in the Oxford English dictionary is .

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