(n) a suppression of certain types of definitions without explanation on a supposedly free Internet forum
Sometimes new definitions submitted to this website become ghost posts; this is a form of Urban Censorship. One tends to wonder why a short and simple definition for one-termer was confirmed but never posted while a huge definition for Operation Iraqi Freedom that rambles on an on for several pages is allowed to remain.
When you can't get your definitions in (DEFINITIONS, not Posts!) onto this website because of something that is disapproved with the UrbanNazis. Also when definitions are automatically erased/deleted without the long Removal process. Also see UrbanVortex or Urban Dictionary Word Limit.
Example of this is the Janet Jackson Superbowl Thing. For weeks, no one can define that on here. Likely a Treacle Effect from Viacom (which owns CBS, which played the Superbowl) down to this very website.