What is Sick Party?
1.
a place, thing or event that is/was of interest or something awesome.
tom: did you end up with that chick last night?
nick: yeh..
tom: oh sick party!
See
2.
A bunch of friends sitting around, wearing those doctor masks or whatever...because theyre sick, and going out in public would be inconsiderate
instead of going to school today, my friends and i had a sick party
See