can be used as a less offensive term for dumbass; a stupid or dumb person.
You're such a freaking dumbbutt!
by Me_Myself_&I April 21, 2009
^informal^
1. something or someone that is considered to be unfair in a way
2. someone who is considered to be ridiculous or that has a butt that is dumb
1. The students thought the teacher's way of grading was dumbbutt.
2. The dumbbutt dinosaur ran right towards the meteor that was about to kill it.
by Spongesquid27 February 12, 2014