A made up word used to confuse people. Can be used to replace words that you have forgotten. A common meaning for durgular is to just say durgular as a definition to piss off people.
Johnny: RU RDY 4 SUM DURGULAR?
Bob: Hell yeah I'm ready for some durgular!
Tim: Dude wtf is durgular?
Johnny: You know, its durgular.
Tim: Fuck you asshole.
Johnny: Don't make me slap the durgular out of you Tim!