A person's collection of pornography. Stack refers to a time when all porn was in print and thus stacked in a cubbyhole in the porn dungeon, equipped with infrared motion sensors, high resolution cameras, lava pits, and crocodile infested waters.

When you eat dirt for the first time and leave your family to build a shack in the woods

Where all the googlewhacks of the world are stored, at the googlewhack homepage.

When "losing it" or feeling as though one is about to "explode". Gained popularity via the constant "whackstacking" of subpar vocalists throughout the hardcore scene.