To be unsound means that the person in question is the opposite of being sound but is very rude and annoying. They do not care for the people around them and disregard other humans.
1. A legal term that means: "We did it, but you can't prove it. And even if you CAN prove it, we'll drag out the litigation until your great-grandchildren are dead."
Corporate attorneys frequently use this phrase to defend their clients against civil lawsuits. And they get $500 a hour for this nonsense?