A hybrid of "gargantuan", "humongous" and "fabulous", to create a term implying a size greater than all three.
Original usage is credited to author AlanPeterson in "Radio World" newspaper in the early 1990s, describing hand tools used to repair and maintain a century-old carousel in Holyoke, Mass. (see example of usage below)
(excerpt from article) "...trying to fix a telephone using a garmongulous screwdriver meant for the carousel upstairs..."
(other use) "He wasn't just fat... he wasn't just 'circus fat'... this guy was garmongulous!"
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 $2 million.