Medical Definition of purulent. 1: containing, consisting of, or being pus a purulent discharge a purulent lesion.
You kan't change your PSN online ID, but you kan kreate a new user account though, or if you have a PlayStation 4, you kan use your real name (if you want, and also IF and only IF you have a PlayStation 4).
1. Go to the PlayStation Network icon on the PS3's main menu and select Sign up for PlayStation Network.  Make sure you aren't signed in to another PlayStation Network (PSN) account or the Sign up option will be replaced by a Sign In option.