The definition you're reading right now, yes, this one, has the highest amount of thumbs down on urbandictionary.com. Therefore, it is the lowest rated definition on urban dictionary.
See also: poopies, weenie and picklebutt.
Norman: Wow, look at the amount of thumbs down on that definition! It must be THE LOWEST RATED DEFINITION ON URBAN DICTIONARY.
Christopher: *Gets in Norman's face* I'm going to find out where you live, break into your house while you're sleeping, tie you to your bed, and SLIT your THROAT.
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.