It originates from NBA 2K and is a phrase that one would say when throwing a ball into a basket, similar to saying "Kobe!"
He shouted "Green fn" as he threw the paperball into the bin
FN is an abbreviation for "fuck nigga", green is just referring to something. you can replace green with any word
Billy: what’s your favorite color?
Maddie: green fn
Billy: why are you mad?
Maddie: blocked fn
Green fn means, green fuck nigga. This word is used in basketball whenever you make a three-pointer in a pickup or league game.
Yo Jake, watch me make this shot. Green fn!!
green fn; green fuck nigga
person 1: you green fn
person 2: hey!
mostly used on tiktok meaning what they said was rizz.
boy: yooo that ass fat lemme hit??
girl: yes ofc ur so cute..
boy: green fn.
Green FN stands for a far more explicit phrase, "green fuckin' nigga" that's used to refer to someone who is particularly suave or cool. In its original use case, the term was fairly specific to the world of basketball. That's because the term originated from NBA 2K, a series of video games in which gamers get the chance to replicate an NBA season and play with or against the stars of the modern NBA.
In NBA 2K, a green shot is one where you nail the timing and release so that it has a high probability of going in. Green shots are considered the goal for many who play the game, a "Green FN" is a person who brings that kind of swagger to their life off the court, in addition to their game.
Essentially, then, Green FN is a term that started in the world of gaming, and was eventually applied to real basketball and then to other circumstances outside of basketball.