Longest word in common english:
Longest word in official english:
Second longest word in official english that also means "Fear of long words":
Longest word in scientific english (probably the longest word in the world):
This word is the scientific name for a protein called titin.
Honestly I think my computer would crash if I tried to copypaste it here or, if not that, then Fandom wouldn't let me. I could put a link to a wikitionary page that has it but I'm warning you, you'll probably lose all your braincells by the time you finish 1% of the word (it's 189,819 letters long).