Kookie is one of the most common nicknames fans will hear for Jungkook. It's obvious where that name and other nicknames (like Koo and Jungkookie) come from. Obviously, they're riffs of his stage name. Golden Maknae nods to the Korean word “maknae,” which refers to the youngest person of a group.
 
Copyright Disclaimer under Section 107 of the copyright act 1976, allowance is made for fair use for purposes such as criticism, comment, news reporting, scholarship, and research. Fair use is a use permitted by copyright statute that might otherwise be infringing. Non-profit, educational or personal use tips the balance in favour of fair use.