adj. describing something that is so dorky, nerdy, or simply uncool by conventional standards that it becomes cool in an interestingly subversive manner.
It is imperative that the direct object in question only have a questionable reputation by mainstream standards, and not be all encompassingly uncool.
"Glish" can be used to describe things (particularly music and movies), places, activities (specifically behavior), and people. When used to describe people it is generally to give the connotation that this is someone who is not traditionally attractive, and has a unique, unconventional beauty/hotness. It can of course just mean that they are quirkily cool.
Adam Brody (and other nerdy-cute boys)is so glish!