similar to the original definition of fuckface, accept for the fact in this case, you only have one penis for an eye while you wear a patch over the missing penis/eye.
you roll up in your car to a stranger and cover one eye with your right hand and point your index fingure of your left hand at the stranger in front of your other eye. then, you simply ask the person "guess what i am". he confesses he doesnt know. you then say "no, guess!". when he gets frusturated and gives up, you then say "I'm a fuckface pirate, DUH!" then peel off into the night.