undersmell 

To understand.

To comprehend.

-word used mostly by fat, ugly dirty south rappers, i.e. Baby of Ca$h Money, E-40

I'm be sitting on nuttin' but 24's nigga. Ya undersmell?

undersmell by Nuckra May 29, 2003

undersmile 

Euphemism for vagina. Coined by Joy in the TV comedy "My Name Is Earl".

Joy: "We gotta work backwards. Like when you rewound that videotape to see if Sharon Stone really flashed her undersmile."

With "flashed her undersmile", Joy is referring to the film Basic Instinct, specifically the scene where Catherine Tramell (Sharon Stone) distracts her interrogators by uncrossing her legs to reveal a lack of underwear.

undersmile by dee kay April 14, 2008

understall 

(adj.) Taking place—as in anonymous gay sex, usually oral—under the partition wall(s) of a public restroom.

1. I got an amazing understall blow job from some guy in the campus library tea room.
2. I've never seen his face; we've only had understall sex.

understall by Blaze Johnson November 21, 2010

underfell 

UnderFell is an Alternate Universe created by fans. The main idea of it is everyone is their cruel counterparts, and apparently only wear orange, black, and red.

UnderFell is my favourite AU!

underfell by DepressingVoice16 July 6, 2016

Underfell Papyrus 

The Edgy Angry Alternate Universe Counterpart To Papyrus. He's more popular than that cool skeleton and has all the girls, such as Akari.

Akari stopped as Underfell Papyrus loomed over her, an angry expression on his face as usual

Underfell Papyrus by Rainy Melai October 26, 2017

Underskillable 

To understand

I underskillable the concept we learned in math today

Underskillable by ScottyParker123 September 10, 2020

Soft White Underbelly 

The bus terminal at Union Station in Denver, Colorado.

He took the 15 to Soft White Underbelly to pick up some clr and blues.

Soft White Underbelly by spigotthebear February 17, 2023