Brainus

noun - the pseudo-brain you have in your anus, that you inadvertently use to make stupid decisions or make you say stupid things, as opposed to using your actual brain. (2)Name used to describe someone who used his/ass and therefore "brainus" to make a decision that was stupid.

That's using your brainus... idiot!
Nice work on that one brainus.

by Jonathan Ainslie August 13, 2006

Brainus

The occurence of putting one person's testicle(s) inside another person's anus.

He gave her the brainus.

by Roddy von Seldeneck May 19, 2007

Brainus

Combining words brain and anus.
aka...having your head up your butt.

Honestly, I really do not know how I came up with that figure, must have been using my brainus that day.

by Motosaki410 June 5, 2019