The identity of the longest word in English depends on the definition of a word and of length.

Words may be derived naturally from the language's roots or formed by coinage and construction. Additionally, comparisons are complicated because place names may be considered words, technical terms may be arbitrarily long, and the addition of suffixes and prefixes may extend the length of words to create grammatically correct but unused or novel words.

The length of a word may also be understood in multiple ways. Most commonly, length is based on orthography (conventional spelling rules) and counting the number of written letters. Alternate, but less common, approaches include phonology (the spoken language) and the number of phonemes (sounds).

The word has the followings below:
Letters: 189,819
Meaning: The chemical composition of titin, the largest known protein
Claim: Longest known word overall by magnitudes. Attempts to say the entire word have taken two to three and a half hours.
Dispute: Technical; not in dictionary; whether this should actually be considered a word is disputed.

NOTES: This word has 189,819 characters in its name and takes almost two hours to pronounce.

In short form of the word is: ±methionyl…isoleucine

I try post the full word here, but the section box can't contain it. Below is the link to the longest word in English.

https://en.wiktionary.org/wiki/Appendix:Protologisms/Long_words/Titin

There's no way that's even a word. I almost dozed off while scrolling just so I could see the end of it. Some lengthy nonsense

I thought it's Anti-geo-gra-phi-ca-tionalism?

That's not a word abeg

Just repetition of protein glutamy isoleucine and co


The longest English word is pneumonoultramicroscopicsilicovolcanoconiosis

jaeyking:
That's not a word abeg

Just repetition of protein glutamy isoleucine and co


The longest English word is pneumonoultramicroscopicsilicovolcanoconiosis

this word has 45 letters

check the link below to see the list of longest words

https://en.wikipedia.org/wiki/Longest_word_in_English

The longest word in any of the major English language dictionaries is pneumonoultramicroscopicsilicovolcanoconiosis (45 letters), 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. The word was deliberately coined to be the longest word in English, and has since been used[citation needed] in a close approximation of its originally intended meaning, lending at least some degree of validity to its claim.

The Oxford English Dictionary contains pseudopseudohypoparathyroidism (30 letters).

There is also a 36 or sn letter word, Hippopotomonstrosesquippedaliophobia: i think the fear of long words

Imagine where you have to write this in an exam.
But seriously I don't think any student can cram this