Top definition
An instance where, no matter what you say afterwards, saying (absolutely) anything in defense of yourself will just make the situation much, much worse. If a brain bomb occurs, it is best to shu your trap and either

a: take the aftermath as a man, or
b: get the hell outta dodge.

Most commonly, this is done by a man to his wife, or by a man in general.
Instructor: ...What could possibly have driven this female to do such a thing?

Male student: Must have been that time of the month.

All female students in the room: *Gasp*

Male student: Damnit, brain bomb.
by Boxymoron2 March 22, 2006
Get the brain bomb neck gaiter and mug.
Apr 28 Word of the Day
Literally everyone, ever. Including the writer of this definition.
by masokitsune January 17, 2019
Get the stupid people neck gaiter and mug.