look up any word, like full-donald:
 
1.
the elaborate, costume-like preprations undergone when a group of girls gets dressed and puts on outrageous levels of makeup and perfumed body mist for a party.
"I can't take a shower, it's Shalloween in our dorm bathroom right now."
by teapartyanimal September 14, 2009
 
2.
The Celebration Of A Holiday Rendered Meaningless With The Sale & Distribution Of Confections
Hotz: "Wazzup, Wut You Foolz Doin' For Shalloween?"

Elmo: "Nuttin' We Jus' Gon' Chill And Batch Up Instead"
by El Cyd 207 February 02, 2007