It's a handy word that easily explains a big gap in your evening of drinking. When you went from drunk and aware, to drunken and unaware, but then got busy with missions that can't be pieced together the next day.
I woke up outside my own house cuddling a wheelie bin, covered in glitter, wearing budgie smugglers over jeans and holding the reins to a miniature horse. Man, I was so drunken last night.
This is used when one is very tired, usually due to excess tiredness, and drunkeness behaviour. Sometimes tracks like 'jump around' are involved. One gets awfulgrumpy.
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.