When one, in a fit of frenzy/drunken euphoria, shouts something at the top of their voice and subsequently smashing a glass/bottle over their head and rendering theirself unconcious.
Billy: "Dude, did you hear about Gary last night?"

Sam: "No, what happened?"

Billy: "He went down to the club and got totally pissed! Then 'Smack My Bitch Up' came on, and he got real excited, shouted "Let's go fucking mental!" and smashed his glass over his head."

Sam: "Oh shit! Really?"

Billy: "Yeah, it was a total shout'n'out. I almost died laughing."
by Scekhcsy Foxmonk August 12, 2010
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