six-by-eight 

A jail or prison cell.

The average measurements of a jail cell is 6 feet by 8 feet.

You better start talking, punk. Or you'll spend the rest of your days in a six-by-eight.

six-by-eight by coochiemuncher September 16, 2019

"I’ll be out the gate by eight / in the spoon by noon / fixed by six / and back in the pen by ten!” 

The heroin junkie merry-go-'round:

Release from prison-back to using dope-re-arrest.

The addict's vicious cycle.

Johnny Threefingers: "Heard you're getting out of this craphole today."
Harry Hophead: "Pfft...well, I'll be back...you know me, man... ""I’ll be out the gate by eight / in the spoon by noon / fixed by six / and back in the pen by ten!”"

"I’ll be out the gate by eight / in the spoon by noon / fixed by six / and back in the pen by ten!” by TopCop May 13, 2014

Eight By Six 

A term a man, particularly a gay man, might use to describe his penis in length and then by width (sometimes meaning girth or circumference), in inches (20 by 15 cm). He's lying, of course. Or at least, no more than a two percent chance he's in that territory.

If he claims six by eight (six long, eight "wide" or perhaps in circumference), you're getting into choad territory. See choad also spelled chode. Demand immediate proof.

.

"So he told me, 'I've got an eight by six.' At first I thought he was talking about a new kind of car engine, or something. I finally figured out what he meant, but he had already proven himself to be such a jerk that I had no desire to check out that particular attribute."

Old Joke -- Q: What's a Gay Eight? A: Six inches.

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Eight By Six by al-in-chgo March 1, 2010