Underfucked 

sexually deprived

1. Yo look how hard she's hitting on him... she's definitely underfucked!

2. That guy is completely underfucked. He just desperately asked her out again after she told him to fuck off for the third time...

Underfucked by Stephen and friends June 26, 2010

underfuckingstand 

When you don't understand something and you are super pissed.
When you don't feel like saying "fucking understand"
When fucking understand just doesn't quite display the needed emotion.

"I don't underfuckingstand why your acting like this"

underfuckingstand by Desiree Aho January 9, 2008

underdecking 

conspiring against an authority figure to take synchronized shits underneath said authority figure's deck. Usually performed in groups of two to five people. In extreme cases, shit burritos are fashioned with paper towels and left to be found.

Oh, no. Have you seen the kids? I hope their not underdecking us again!

underdecking by underdecked July 2, 2009

undrunkable 

the inability to feel drunk during a day/night while drinking heavily. Usually occurs the night following a hangover.

Many have tried to fight this condition by keeping on drinking despite the lack of effect, this usually results in getting sick before feeling drunk.
The irreversibility of this condition has been disputed as some claim to have succeeded in eventually getting drunk.

tom: dude, last night was really lame
mike: really? i heard everybody say it was a sick party!
tom: well, maybe it was, but i was undrunkable..probably from drinking so much the night before...anyway, i gave up after a couple hours and just went home

undrunkable by yeahprobably June 17, 2010

Cuban Underduck 

When you bend your dick down and back, and a girl blows you from behind with her nose on your butt hole.

"I got a dandy Cuban Underduck from the broad I met at the bar last night."

Cuban Underduck by TurdFerguson21 June 3, 2016

underfuckingstand 

underfuckingstand - Understand, with "Fucking" inserted in the middle, making it an exclamation of frustration or, in some cases, a joking statement.

"What part of this do you not underfuckingstand?!?" or "I dont underfuckingstand!"

underfuckingstand by Steve October 24, 2004

underdrunk 

The unpleasant experience of not having the adequate time/resources to achieve one's desired level of intoxication.

Fred: I'm overworked and underdrunk.

underdrunk by Jeffrovich January 6, 2009