Common insult with obvious implications. The insult is meant not only to indicate someone who who is stupid and / or offensive, but also one who would do an act which would render their breath like someone else's butt.
Hey, butt breath! Move your car.
by Frank Klaune January 23, 2005
A person with such extreme halitosis that their breath can be smelled all the way across a large room when they are speaking.
Gene has buttbreath all the time - it must be that diet of coffee and donuts.
by Rod Brock July 27, 2006