Urban Dictionary: main vein

"Be right back, I'm gonna go drain the main vein".

"I drilled her with my main vein".

by mickyxtee May 09, 2009

by Xeroman November 23, 2015

The largest vein in the penis. Once the penis has become erect, the blue/purple vein becomes clearly visible.

"Seeing that chick naked got me so hard that my main vein was just bulging!!"

by PMchoisi June 08, 2009

The large vein that travels the length of a cock. Instrumental in delivering blood from the central artery during erection.

My cock was so hard, my main vein was swollen with blood.

I saw my heart beat as the main vein of my cock pulsated with blood.

by Tony from the Lido September 21, 2011

Slang for "Urinate"

"The Main vein" being the penis of course.

by Doc Evil July 24, 2003

To snort a line of cocaine off of a fully erect penis

Me: Yo, do you even rail the main vein?
12 year old on Xbox live: Yeah, fucker, I rail the main vein every day!

by Blawkz February 09, 2015

An event which occurs when one woman is with five men at the same time. One in the pink, one in the stink, one in the mouth, and one in each hand.

Did you see Jessica go off with those five guys last night? She must have ridden the main vein pain train!

by Job Skywalker September 04, 2011