Phrase describing a person who lacks the collective intelligence of a box of rocks; possibly a bit more intelligent or a bit less intelligent than a person who is dumb as a rock.
John lit a match so he could see where the gas was leaking out; he's dumber than a box of rocks.
Nickname given to bales of marijuana thrown overboard or out of airplanes. Origin is reportedly from members of the US Coast Guard in the area of Southern Florida.
A sunburn or suntan focused on the left arm. It is caused by the left side of the body being the only half that gets exposed to sunlight while driving. Presumably, it would be located on the right side of the body in countries where they drive on the left side of the road.
I had a trucker's tan after driving for 10 straight hours on a sunny day.