someone with about half the mental power of a person with down syndrome, someone that can't see their stupidity when it's pointed out to them, a dim bulb in slow motion, a mental midget
you're either subretarded or a weaktroll, I can't tell yet...
The state of mind engendered by any level of sleep deprivation, most notably accompanied by a highly likelihood of laughing--often hysterically--at something that, with a normal night's sleep, would normally be categorically unfunny.
I don't know what that kid just said, but I'm subtarded enough to think it was funny