A stupid person; it refers to the lack of surface area on an individual's brain. The general thought is that the more surface area (wrinkles, creases, etc.) a brain has, the smarter the person is. Conversely, a person with a smooth brain (no wrinkles) has less surface area and would therefore be stupid.
That fucking smooth brain put his shirt on backwards again...
That smooth brain is dumber than a pile of shit.
Someone who's being a retard or doing something retarded.
Stop being such a fucking dick dong...
A mentally challenged child; a retarded toddler.
One day that little tardler will grow up to be a full-blown retard.
Very large breasts capable of giving you a concussion if you stuck your face between them and the chick violently bounces them back and forth against your head.
Dude! Look at those tits...definite concussion makers!
The combination of male load and egg nog.
Nothing says Christmas quite like a cup of fresh Nut Nog...
To get all-out pwned on the scale of the 2011 Japanese earthquake, the resulting tidal wave, and the subsequent nuclear meltdown.
On March 11, 2011, Japan got JaPWNED!
Hiroshima + Nagasaki + 2011 Earthquake = TOTAL JaPWNAGE!!!!
A bowel movement where all three states of shit (solid, liquid, and gas) exist at the same time.
Dude, that was a massive Triple Pointer...solid shit, liquid shit, and shit vapor all at once!