Underboss 

Member of a mafia family, typically directly underneath the Don. Handles the mundane details of running a crime family.

The underboss put the capo in charge of making sure the hit was carried out.

Underboss by Roberto Manchez December 29, 2004

underbugger 

A person or annoyance that gets under ones skin and bugs them.

That squeaky door is a real underbugger. I think that new girl is an underbugger, she wont shut up.

underbugger by Christopher Evans August 2, 2008

UnderLust 

An alternate universe of the game UnderTale containing almost everyone as lust filled monsters, and Mettaton EX as a shy talk show host.

UnderLust was created by nsfwshamecave on Tumblr.com

UnderLust by DepressingVoice16 June 28, 2016

undershirt 

1. what manuel neuer never fails to wear on pitch.

2. it is the teasingly thin cotton shirt usually seen worn by usually hot-the-ones-you-fancy footballers underneath their jerseys.

3. it is the very thing that most fans(girls) hate to see once the footballers pull off the shirts after the match.

4. it can be used as a test to see if a girl is straight or not. nuff said!

...after a germany game...

fangirl 1: hey look manu is pulling off his shirt! urgghh what's that thing he's wearing?

fangirl 2: why it's the undershirt!

fangirl 1: but he usually wears long-sleeved. i don't get why is it even necessary...

fangirl 2: yeah manu is mean. he needs to start attending the fanservice lesson.

fangirl 1: he so does. undershirt must be banned!

...both fangirl 1 and fangirl 2 started to appreciate schweini...

undershirt by inlovewithneuer September 2, 2010

Underbus

Verb used to describe the act of "throwing someone under the bus" or otherwise admitting someone's wrongdoing for them.

My sister was in trouble with my mom, so she underbussed me for something I did last week, and got herself off the hook.
An underbusser is a grown tattletale.

Underbus by misshappenstanc October 9, 2017

undershirtable 

The ability for an often-times too small t-shirt to be used exclusively as an undershirt, mostly worn under polos. This term refers mostly to preppy teenage males but it can apply to many different male groups.

Walker: Man... I was brushing my hair for the third time this morning and I noticed that this T-shirt is way too small for me now.
Trey: Don't worry, its still totally undershirtable. I've got like a whole closet full of them.

undershirtable by Tate Thomas July 4, 2008

UnderBum 

1. When a female wears really short shorts and reveals the underside of her ass to passers by.

2. God's gift to ass men.

3. Also known as ass cleavage.

Adam: holy shit that chicks ass is hanging out! I think my dick just moved.

Craig: That my friend is some grade A UnderBum.

UnderBum by Hector the molester July 28, 2010