Underground Railroad 

The act of two males having intercourse with a single female a.k.a. "running a train" while under the bedsheets. An underground railroad is exclusively when this act is done by African Americans.

"Yo, I heard you and your bro ran an Underground Railroad on Shanockquolisha last night!!"

"Hell yeah! That sh*t was insane!!"

Underground Railroad by TheOneAndOnlyHalfnHalf October 2, 2011

Underground Railroad 

The sexual act of going down on a girl and vaping into her vagina

My boyfriend cannot stop vaping! Last night he vaped in my pussy and called it and Underground Railroad. It kinda tickled though.

Underground Railroad by Chu Chu Twain March 28, 2016

Elevated underground railroad 

The part of the subway that runs above ground.

The black people were in plain sight of the racists while on the elevated underground railroad portion of the underground railroad.

Elevated underground railroad by Solid Mantis November 25, 2020

Underground Food Railroad 

n. the secret pathway that you put your extra food on when you're at somebody's house that does not like to waste food. In the Underground Food Railroad, you must work as a team to get rid of the extra food. This is usually used when there is a buffet and you accidentally get too much food.

I got too much food at the buffet... Granddad will be mad...I think I'm gonna use the Underground Food Railroad...

Underground Food Railroad by kk4444 December 25, 2010

underground railroading 

The act of scissoring assholes and transferring shit from one anus to the other

Guy 1: "What did you two do last night?"
Guy 2: "We were underground railroading until our asses overflowed!"

underground railroading by thechocolatestarfish April 28, 2014