the violation of an object, person or media form that your generation holds sacred. Usually displayed by defying the excepted norms of your age (i.e. not worshiping the teen idol of your era or not watching the most popular TV show of your childhood).
Isaac: I like Alien Antfarm's version of Smooth Criminal better even though MJ is the orig...
Jeanne: It's okay, Isaac - I like the Seether version of Careless Whisper to that of George Michael and that's pretty much generational sacrilege but I'm comfortable with my choice.
Using something the wrong way. Like making your dog walk you, or playing a violin upside down.
Kid1: Bro!! What are you doing with that pig!!
Kid2: Putting pepper on it so I can make Peppa Pig?
Kid1That's some sacrilegious shit.
Kid2:Yep some classic sacrilege!