The Rice University Neologisms Database

An abbreviation for God Damn Independent, a derogatory term used by fraternity members to refer to students not involved with fraternities. At many colleges where fraternities and sororities exist, those who choose to not be involved in Greek life are looked down upon disdainfully by those who do. The term GDI was apparently created to allow non-GDI’s to talk about GDI’s in front of their faces without their knowledge.