An extreme sport in which an individual slides down a rail, usually in a staircase, perpendicular to the rail, balancing on the lower ribs and upper abs. The two variations are sprints, in which a single rail is ridden down, and slalom, in which a series of rails going down a stairwell that rises at least 4 floors.
As he rounded the last corner of the stairwell, a police officer almost grabbed him, but he quickly remembered abdominal surfing, so he lept onto the last stair rail and ab surfed away
by bad mother lover September 17, 2010