Word used to describe an asshole when specifically suggesting that the person is the tube-like, shit-covered skin within the anus, rather than the air between it.
That guy just stole my seat! What an ass tube!
by Carton Jones December 16, 2008
the lower part of the digestive track adjacent the anus; the rectum
If you have rough anal sex then you may end up with a sore asstube for a while.
by real id guy June 07, 2009