The phrase is used to describe the glass basement in IQ for men. At the opposite side of the IQ scale from The Glass Ceiling lays a «Glass Basement» which is the idea that while Males have the highest/ more distrubuted IQ levels, they also have the lowest.
The glass ceiling is discussed so often that people forget about the glass basement for Males.
A noun describing a freakishly cool wierdo, very likely a zinester, or someone soon to become a zinester who currently lives in a basement, or lived a large portion of their adolecent lives in a basement.
Anarchy Ashley, maker of the zine 'Alien Basement Food' is a prototypical basement freak.