A sexual toy that is inserted into the anus...preferably "vibrating". Often available with a "safety tether".
As I walked away from the mirror I found that my butt egg had become disengaged due to its safety tether.
by mto March 28, 2007
The things that come out ur ass. Jobie, shit, crap. whatever
Man I was on the bog for hours layin a huge Butt-egg
by Marshall Law November 12, 2004
a preson who is being really stupid, annoying or dumb
"your a stupid buttegg"
by Bricole April 14, 2006