An insider term for a 'party' people in the know, who are going to the big party this weekend. Popularized in 1990, in Fort Mcmurray Alberta. Way before Snoop Doggy Dogg used the term 'Biatch', I think.
Eric: "Why do you have that Texas Mickey of Bacardi Rum?"
Megan: "Me and the girls are going to the big Piarty over in Thickwood Heights."