Racial slurs!

[Angrboda]

Well, in the interest of addressing our racist idiot bully's points, I figure I may as well dissect it.

Are we allowed to use racial slurs here? Of course not. 

But what is a racial slur? 

Here's how the OED defines that particular variation on "slur.": an offensive term used deliberately to show a lack of respect for a particular group of people. Presumably, a racial slur would be one that shows a lack of respect for a particular group of people specifically because they're from a different race.

It's worth noting that the operational definition of a slur employed by this forum is not that of the OED and differs in significant aspects.