To totally kick someone's arse, especially when using Matrix-like skills.
As a past verb: "Holy shit, did you see that guy go Keanu on his ass!?"
Present tense: "Fuck, he's going Keanu on that guy's ass!
Future tense: "I'm so going to go Keanu on his ass when I see him next."
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.