assmosis 

When two people engage in anal sex.

(called "assmosis" because the two lovers are absorbing each other's pleasure as they bump their ends)

Derived from the word "osmosis."

Okay cowboy, let's go make love on the couch via assmosis.

assmosis by Mark H May 22, 2004

assmosis 

the process of one's butt getting bigger just by standing beside those with bigger butts.
People with fat friends get bigger butts just by being around "fat asses"

Julie's butt got bigger every time she was near Jane because of assmosis.
I can't help that my ass has gotten bigger; it was assmosis.

assmosis by Serena Peterson January 3, 2009

assmosis 

the gradual or unconscious assimilation of ideas while sitting on one's posterior in a classroom setting

While sitting and listening to the long lecture I seem to have retained much of the content by the process of assmosis.

assmosis by herbybell April 3, 2010

assmosis 

the process of one's butt getting bigger just by standing beside those with bigger butts.
People with fat friends get bigger butts just by being around "fat asses"

Julie's butt got bigger every time she was near Jane because of assmosis.
I can't help that my ass has gotten bigger; it was assmosis.

assmosis by Serena Peterson January 6, 2009

Assmosis 

It’s when a shit sits in a toilet bowl for too long and starts to dissolve and turn to shit water.

AJ: My fucking roommate left a shit in the bathroom this morning and I think it was clogged. I swear when I come back, it better not be there.
Isaiah: Nah, it’ll be shit water. What’s the term? Osmosis?
AJ: Assmosis

Assmosis by MotherfuckingSatan August 27, 2019

ASSMOSIS 

/ˈæs·moʊ·sɪs/
colloquial; pathological hygiene myth

Definition:
The delusional belief that standing in shower water alone effectively cleans the human anus, negating the need for direct contact, soap, or scrubbing. Most commonly found in adult males raised in environments where touching one’s own ass is considered a gateway to eternal damnation or mild gay panic.

“Yo, I ain’t tryna go near my hole like that, bro. The water gets it.”
"Bro that's not hygiene...That's assmosis."

ASSMOSIS by Faceofadeadstar July 21, 2025

Reverse Assmosis

The process of previous farts in a seat, chair, couch, etc reverse cycling up someone’s butt and being farted again.

Dude, someone must have been ripping ass in this seat because I’ve got some serious reverse assmosis going on right now.

Reverse Assmosis by BDE84 July 20, 2018