Underbell 

The underside of one's penis, usually towards the end.

Ouch my underbell!

Underbell by Tomujs August 7, 2012

underbeneath

The practice of sporting your collar tucked in, typically in crime-riddled urban areas. The polar opposite of the collar pop. Made popular by Atlanta rappers "Tha THC Boyz" (They*Hidin*Collaz.)

Damn, son...You wanna get shot?! You better tuck that collar underbeneath!!!

underbeneath by Loloforeal June 12, 2007

Underblown

1. Opposite of overblown. When you feel things are worse than what is stated.
2. A guy in serious need of a BJ

Guy 1: I think this covid thing is overblown.
Guy 2: Oh yeah, I think it’s underblown.
Guy 1: You’re underblown.

Underblown by An1ta Hummer June 23, 2021

Levi underhill 

A HANDSOME CHARMING MAN WHO LOVES AND CARES FOR HIS FANDOM

Hill: WE LOVE A GOOD LEVI UNDERHILL

Levi underhill by The realest shishtar February 22, 2019

undertall 

A condition caused by the height and weight ratio not working out just right.

She's not overweight, she's undertall.

undertall by cowboy_up September 4, 2009

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