Acronym for "God Damn Independent," often used in a derogatory way to refer to a college student who chooses not to join any sorority or fraternity.
Seems to be used in a derogatory way the most by people affiliated with the 'Greek' system because they do not realize that 'independent' really isn't even an insult. Typical brainless, follow-the-crowd, frat people. Damn, frats and sororities are like cults. People go in fine and come out brainwashed, dumb, and/or slutty. IF they ever come out.
Vic: What's your title?
Vic: You know, what frat are you in?
Sam: Oh, I'm a GDI.
Vic: Wow, I really think you should go Greek.
Sam: You know, they're not even really Greek. They just jacked the Greek letters and twisted them to use in their half-assed, drunk-partying organizations. I only rushed for the free food. You'd have to pay me to join one.
Vic: Why don't you join?
Sam: Um, it costs money I can't afford to waste, I can make friends on my own time, I don't really want to be saddled with people I don't like, I don't like to do pointless shit, and I don't like how they always call each other 'big' and 'little.' It's hella annoying. Oh, and I don't really like to conform.
Vic: What's 'conform?'