Saying that someone lost a fight very badly (perceived as a knockouts) or has been jumped by more than one person.
Usually used to promote the "winner" of the fight and to embarrass the "loser".
(This could happen to one, if one is chilling in the "wrong neighborhood" knowing one is not suppose to be there because one had somehow offended people in the past.)
Jerome: Remember Terio from gym class?
Ryan: Yeah the big kid with the afro?
Jerome: Well, I heard he's been texting my gf so I came up to him and asked him if he knew who I was and when he said yes, I straight up splacked him side of the head and he dropped in the middle of the cafeteria.
Ryan: Damn son! That n*gga got splacked for real. Remind me next time not to mess with you.
ADJ: to be very intoxicated and extremely suped at the sametime.
ADJ: During happy hour, Sue was so shlacked that when her co worker punched her in the face, she hugged him and said, "we need to hang out more often!".