The meaning is quite varied.
it is always postive though...
it can be often said in the form 'blursh' which is a word which you prnounce at unpredictable times for no reason whatsoever.
Also in the form of blursh, it can be used as a positive noun.
1. "omg that is so blurshy!"
"Wtf are you on about?"
3. "Well isnt that a little piece of blursh"