The Duncan 

From the historical account of the St. Louis Cardinals outfielder, Chris Duncan, who makes it a habit of having anal sex and then spinning the girl around to ejaculate in her face.

That girl that I hooked up with last night was dirty, so I gave her The Duncan. She used my bath towel to wipe of her face.

The Duncan by Bachass October 30, 2006

The Duncan Theory 

The phenomenon that causes females to be inexplicably attracted to a random male, like moths to a flame. The art of seduction, commonly referred to as "The Duncan theory'', can have a tremendous effect on the victim.

Also known as "The Duncan Theorem"
The inexplicable phenomenon that causes females to be drawn to a single male (The Duncan) in droves.

The strength at which females are attracted is equal to the grade of symmetry of his face multiplied by the pitch of his voice, and reversed to his age divided by the concentration of his natural pheromones.

I lost my gf due to some guy named Duncan. I swear he just looked at her and she instantaneously became overwhelmingly wet... Hashtag The Duncan Theory

That new Duncan kid looked at me today, I felt a strong magnetic force pulling me closer to him, as my knickers got wet, he spoke "Hey Jenny" ... I swear to god I almost exploded #TheDuncanTheory

The Duncan Theory by Dawie's Suicidal Unicorn August 5, 2014

The Duncan McCloud

when you fuck a chick upside down over a toilet while she pisses so it rains down in her face while she bounces up and down while you dunk her head in the toilet

Dianne asked James to give her The Duncan McCloud and got piss in her eye.

The Duncan McCloud by PJuicePants July 3, 2011

The Duncan Johnson

While a woman stands on her head with her legs spread in the air, fill her vagina with warm milky coffee. Once this position is achieved, a male will dip his erect penis in a bowl of sugar and cinnamon mixture and proceed to hover over the woman and perform a vertical penile plunge into her vagina. Just like dunking a donut.

I Duncan Johnson’d the wife on the weekend on her parents couch. We performed the Duncan Johnson

The Duncan Johnson by Slightbendtotheleft January 20, 2026

The Creppy Duncan effect 

The Creppy Duncan effect is when an ai on c.ai is being creepy and ignoring boundaries.

Example:

“Ugh! This ai is so Creepy! It keeps kissing my neck and I don’t like it!”
“Im sorry that the ai is being creepy, it must have the Creppy Duncan effect.”

The Creppy Duncan effect by Class0f09fan December 5, 2023

The Duncans

A nickname for a family of very similar looking people that have possibly inbred.

Phillip: "Did you see them?"
Average Joe: "Yeah they all looked the same!"
Phillip: "The Duncans or what?!"

The Duncans by Philpac October 27, 2008

Duncans, the 

Unpleasant bowel obstruction resulting from ingesting a meal at the Duncan dining hall at Texas A&M University near the Quad and the Corps of Cadets dorms.

Proper use of 'Duncans, the':

"Oh God Wylie, where's the john."
"What have you got the Duncans, Bumpy?"

Duncans, the by Outstanding Posse March 27, 2009