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Ruthless, but in an extremely cool way. Possessing qualities similar to the Sith in George Lucas' Star Wars film(s).
"WTF?! Samir just knocked that guy out with his limo door!"

<lol> "Damn, that fool is Sithcore."

"Hey, you check out the new KOTOR beta?"

"Yeah, that shit's Sithcore."
by Darth Sarcasmus February 03, 2010