1) A person who is physical and mentally incompetent of keeping up with "common sense" by acting like he is 5 yrs old but in reality is much, much older. He may not know he is acting this way, but clearly the people around him do.
2) A female dog without a father. The father presumably being shot down during Vietnam.
3) A half bitch, half bastard creation.
''Listen here you incompetent bitchtard, start acting your age or you'll be feeling the full force of my boot entering your fucking skull''