Every once in a fortnight, it's useful to actually help GDIs. It's a shocker, sure, but it can also help non-GDIs differentiate between terms that are, at times, somewhat ambiguous. Here are helpful hints so you know what the eff you're talking about:
GDI- Plain and simple. A GDI decided against pledging. It's pretty simple and is the term where all variations come from.
Geed- This is pretty much synonymous for "lame loser who loves even lamer things". It gets confusing when you tell one of your otherwise non-Geed friends that he's acting like a Geed, being a Geed, or you tell him to stop being a Geed. This is the term you use when you need to wake him up from his slumber. Saying, "Stop being a Geed" is a call-to-arms. If you are in a fraternity, you can still be a Geed, just not a GDI (because you are not an Independent... you pledged, get it?). Don't toss this term around lightly, because the wrong person can take it the wrong way, and your ties of friendship could potentially be forever severed.
Geedasaurus, Giganti-Geed, Supergeed, Rumpelgeedskin, Geed Laureates- These are all examples used for a special class of Geeds or GDIs (yes, can refer to standard GDIs or Geedy friends). Much like fraternity guys are split into different echelons of sweetness, GDIs and Geeds are divided into categories of lameness. And these guys are at the top. Maximum geed levels are achieved by all.
Anal Geeds, Geeds R Us, Frisgeeds, Geedters- These are terms used for a grouping of Geeds. They differ in their level of cleverness (Anal Geeds is a variation of Anal Beads, for example). Groups of Geeds increase in danger as their numbers increase. Avoid avoid avoid situations in which there are large groupings of GDIs (unless you are using Hit-N-Run tactics, such as quick-hittin' thievery).
And then, there's this fuck-tard:

For some reason this no talent asshole is loved by GDIs and Geeds everywhere. He fucking sucks and don't waste one single breath on him.
-He should "Hung" himself.
(Sorry)
(Naht).