Someone, or something, beyond the normal realms of retardation, fotardation, botardation, xtardation. This entity is so supremely "tarded" that it is, in all likelyhood, not real.
A retarded person that has the last name "Quintin". Usually this person is described as oblivious to what's going on, sometime thinking something bad is good, and just overall retarded.
Quintard: "Okay guys, quite down. Here's your test. No cheating."
Student 1: *Gets handed test*
Student 2: *Gets handed test* "Yo what's the answer to the multiple choice."
Student 1: "I'll tilt my paper up and you just stand up and look over my shoulder to see my answers when I'm done while I'm "double checking"."
Student 2: "What? Won't we get caught?"
Student 1: "No. Our teacher is Quintard, she doesn't know what the fuck is actually happening."
Simply put; a quagtard is the combination of a queer, a fag, and a retard. Although very politically incorrect, it has a very precise application. It describes a closet homo, who tends to allow his OCD to rage out of control, all while being queered on a regular basis while simultaneously being one of the dumbest human beings on the planet.