An ordeal that lasts a short amount of time, but requires a great deal of skill and concentration to successfully manage, especially near its completion.

Named for the climax scene of Star Wars Episode IV: A New Hope.
"A week of exams with Physics and Calculus on the last day; that's one hell of a trench-run!"
by Jacob Gibbs June 24, 2006
Esp. with a large woman, lay the pen0r between the ass cheeks and masturbate with them. Just before you ejaculate, say "Use the force Luke", and then spread and aim for her exhaust port.

Extra points for painting the pen0rlike an X-Wing and your balls like Tie-fighters.

Deduct points if you bullseye her "whomp rat".
"I did a trench-run on Lisa last night, she growled like a wookiee"

by Zippo August 8, 2003
The act of finishing in a woman's mouth (thereby dropping your "proton torpedo") after a vigorous period of thrusting your member between her breasts (also known as "titty fucking").
Dude, I went trench running on this busty chick last night. Pretty sure I get bonus points for doing it vertically.
by Sterling Cooper December 5, 2013
(n.) A man sticking his penis in the belly folds of a fat woman and running it along the equator.
I gave that chick last night a Death Star Trench Run. She was so fat I couldn't find her thermal exhaust port.
by Sardie November 15, 2011
The Trench Run involves spreading the asscheeks of a hot woman, and in one fluid motion, pass your nose and mouth between while simultaneously spitting into her “exhaust port.”

The name is a reference to the famous scene in Star Wars: Episode IV A New Hope, in which Luke uses the Force to direct shots fired from his X-wing into the exhaust port of the Death Star, resulting in its subsequent explosion.
Her butt was looking so good. I did a Trench Run right through her ass cheeks. The Force guided my spittle precisely into her tight asshole. Under my breath I uttered, “The Galaxy is saved.”
by Showstick September 25, 2018