short form of "disconnected". Usually used in online video games to describe frustration for getting booted from the server due to lag or insane graphic choke caused by noobs trying to run World of Warcraft with a GF2.
c00lguy_23: wtf? laaaaag! ffs dc'd!
h4x0r: lol! n00b!
There is two types of dc'd, One is where you may disconnect from the internet. which may end your browsing session or your online game.
Or, to be hit in the face with a pair of Dc shoes.
Dave: John, why is your nose bleeding?
John: Dude. a insane Guy just came along and Dc'd me!
EpIcSnIpEr123: Dood im laggin.. ffs! dc'd
EpIcBeEn: Oh... we lost becoz of you dc'in