Having sex with a woman having her period. (while on the rag) Kind of like when a person has sex in an airplane to become a member of the mile high club.
Brett K. planned to become a member of the Ralph Club by having sex with Becky during while she was having her period.
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.