(1) Of, or related to people born and raised to being like a South American or in South America.
(2) Being really good at something that most people consider "impossible" or flat out insane. Ex: Playing girls, playing soccer, doing crazy ass shit but not hurting themselves like other jackasses, and all the good stuff.
(3) Very good quality, or comical quality
Example 1: I'm South American because I was born and raised there and my friends South American because his heritage is South American and therefore he was raised like a typical South American would be culturally raised.
Example 2: Ryan: Damn did you see Ronaldinho do that fucking crazy trick then pass it to Messi on Barcelona? Nacho: Yeah man their fucking south american!!!
Also, Ryan: Dude I just did a 720 back flip and landed it!!! Nacho: Thats fucking south american man. Also, Boo: That chicks fucking easy man Ryan: Duh dude, because your south american!!!!
Example 3: Ryan: Dude, sonic is fucking south american Nacho: So is this chocolate dude.