This Phrase, used by downtown Oakville, Ontario teenagers means simply:
Haggard - Completely wasted. Wasted can describe, being high or drunk.
Ass - A fun word to stick in the middle.
Bitch - Replaces the name of the person who is "Haggard."
A Shackteau is a humble, weather-beaten, structurally questionable shelter located in a spectacular or highly coveted place—Wales, Jackson Hole, Sun Valley, Crested Butte, coastal Maine, the Alps—where the building itself may be worth almost nothing, but the dirt, view, access, and mythology make it absurdly valuable.
In use:
Shackteâu - We thought it was an abandoned shed until the realtor called it a rare alpine Shackteâu with unobstructed views and listed it for $2million.