Just chilling or hanging out somewhere, often with others, while leaning on a wall or post and lifting one leg, placing that foot against the surface you are leaning on. Folding the arms is also common, but not necessary.
"Before the bell rang we didn't have anything to do so we all decided to post up on the wall. It was B.A."
by TJCapSix March 08, 2006
Lou and Mike were having a contest last night; they just kept on downing shot glasses full of booze until finally Mike just passed out. Wow, Lou is really the man.
by TJCapSix September 15, 2005
by TJCapSix August 01, 2005