Derived from the word decent, dec is another word for awesome. You can add prefixes and sufixes to dec to make it mean better or worse than it is. Dec as hell!!= really fucking awesome. Pretty dec=not to bad.
it all started one day, when T. Condon and E-Rock were walkin around lighting off fire-works. Mr. Rock asked T. Condon "What are you, an idiot?!?!" to which Mr. Condon replied simply "pairshnuh."