An extremely hard and compacted turd that "chisels" the butt.
"man, after that 12 hour flight, I dropped a butt chisel in the nearest available toilet.
by black coyote December 16, 2009
A person who grinds on your butt day in and day out whether at a job or in a house in comon for their own selfish interests.
Shane the Buttchisel will grind on you until he gets what he wants even if it hurts you in the end...
by Greg Black April 16, 2007