The ultimate extension of the exclamation "Q", meaning totally, stupendously awesome. Only, awesome in the true sense, not in a Bill and Ted way. Much better than that.
"Andi, when you threw you knickers at The Darkness, that was so Q!"
Really, really, really, bad.
"Deirdre, that trucker cap is mean-red."
Something that is totally, astonishingly, stupendously good.
"Deirdre, that t-shirt you got me is most definitely Q."