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2.
noun and verb

when you suddenly have a complete psycho and all logical thought and reason takes a back seat to your rage and anger. sudden act of rage, without premeditation.

dangerous and illogical things happen.
"My god, what happened here?"
"Tim brainsnapped and thwacked him"
OR
"Tim had a brainsnap and thwacked him"

Examples:
Smashing a whole cupboard full of crockery on the footpath cos your plate wasnt cleaned properly. (From: He Died With a Felafel in His Hand)

by chuckles mcdagger February 11, 2008
 
1.
the term used by famous people (and normal people) to justify doing something really stupid that if they'd taken half a second to think about it they probably wouldn't have done it anyway. it's a cheap way of saying sorry for doing something dumb and not taking any slack for it.
the famous celebrity phone throwing incident that everyone knows about - headline of paper "how my brain snapped"
by trinie July 31, 2006