by Phuqit November 12, 2006

One of three categorizations of an answer (other two: anus and brain--see definition); meaning you are not 100% certain that your answer is 100% true
by spintas July 28, 2012

Tom's decision to wear a leisure suit to his father-in-law's funeral clearly came out of his brainus.
by Antonym Antony February 20, 2011

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.
by Jonathan Ainslie August 13, 2006

He gave her the brainus.
by Roddy von Seldeneck May 19, 2007

by Tiahlm September 26, 2007

Honestly, I really do not know how I came up with that figure, must have been using my brainus that day.
by Motosaki410 June 05, 2019
