What’s a mook?
https://www.urbandictionary.com/define.php?term=mook
“(noun) 1: A male adolescent or young adult exhibiting an unpleasant, self-centered attitude, formed during a sheltered upbringing. 2: One who revels in their own ignorance.”
Wow, all of the definitions you posted describe De Nerdo perfectly (with the exception of the word “young” in one)! It’s almost uncanny...and pretty pitiful, lol.