When a guy pops a hard on resembling that of a clock's hands going from 6 to 12 (midnight). Another expression for erect penis.
Dude did you see that hot chick walk by? I'm def. six twelve-ing it.

When she's dancing like that on me, I can't help but pop a 612
by sageberry420 August 31, 2010
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The number expressing black dick
Row: Dude, did you see that fat ugly 612
Dan: Yeah man it was f***** ugly
by I Stalk u June 12, 2010
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When you see something so orgasmic (like walking into a bar and seeing your entire league of kickball teams playing flip cup on 8 different tables, or Bar Rafaeli naked) that you feel as excited as you do when you get hard. Thus, you go from the 6 position (on a clock) to the 12 in your head, hence going from 6 to 12, or just 612. Other uses: 612 mafia - for all those in the know.
Dude, when I saw the Red Sox hit 4 straight homers that one year, yea, 612. But last night when I was too drunk to get it up, I couldn't even get to 630. Good thing too, she was ghastly.
by HomodadNo May 01, 2009
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