Short for "hard-kore", which is a deliberate misspelling of "hard-core", because only
cool people would change a "c" to a "k".
Often sarcastically used to insult or describe someone who thinks they're rebellious, when
they are, in fact, not.
Guy #1: Yo, I went
to a party on the weekend and drank lots of beer, G-dog.
Guy #2: Woah. You're pretty HK.