Someone who is dumber than a box of rocks. Some say it means Bitch On Bars to hide their stupidity.
Boxxx: " why dont they just eat weed brownies.......? they should use that fabric toliet paper roll thing."
Alex: "dude, Nikki, you really are dumb as a
boxxx of rocks. you're lucky you're such a damn cool kid, or we'd have to shoot you."
