U-boat 

A lady's undercarriage - from vagina all the way under to buttocks.

Hannah, are you wearing a onesie?' - 'Hell yeah, dawg. It covers my whole U-boat.

U-boat by fujibo September 3, 2010

U-boat 

(British smoking slang) When you're chilling back with your homeboys smoking up a phat joint, sometimes one will note that one side of the "bifta" burns faster than the other, and will sometimes curl upwards. When this occurs, the joint is said to be a U-boat. This usually happens because of a poorly rolled, uneven joint, or because of excess saliva on the gum side if it has just been rolled. Some synonyms for "U-boating" are "elvising" (in reference to the famous quiffed hairstyle)and "sideying" ( as it is only burnt on one side.)

"What wanker rolled this fucking joint? It's u-boating like a bitch!"

or

"That was a total waste of draw, we only smoked half of it 'cos it sideyed!"

U-boat by MikeTheBritishCunt May 14, 2006

u-boat 

A u-boat is someone who can have an invisible disability and go undetected for years, like a u-boat, or an underwater boat.

So in middle-age, I've been diagnosed with autism. While it explains a lot, I feel like a u-boat.

u-boat by Siouxsie Supertramp November 20, 2023

U-Boat Butterbrot 

German submarine sandwich. Consists of German salami, onions, sauerkraut, pickles, pickled herring, and german mustard (senf), piled onto a loaf of light rye bread.

Hedley had a choice to make. Did he want the regular Italian sub or did he want to risk the U-boat Butterbrot, which like its submarine namesake held the smell of danger about it.

U-Boat Butterbrot by steeplejack November 5, 2010

U-bend U-boat  

A turd that is submerged in the U-bend of the toilet like the german submarines (U-boats) used to hide beneath the surface of the sea. 9 out of 10 U-bend U-boats are unflushable in the average toilet.

For fucks sake, that U-bend U-boat just won't flush! Pass me the bog brush Dave, it turd bustin' time!

U-bend U-boat by MSN NINJA April 19, 2009

Urethral U-Boat 

When a dude decorates his dick as a German U-31 class u-boat, and inserts a projectile, such as a nerf dart, into his urethra, so that when he climaxes into his partner, the projectile will be launched into his choice of holes.

I’m searching for a partner to perform the Urethral U-Boat on.

Urethral U-Boat by VyXious January 12, 2018

Dirty U Boat 

The act of having a dump whilst in the bath.

I was having a nice soak last night, and accidently curled out a Dirty U Boat! It stank!

Dirty U Boat by Ed the Jeb November 27, 2011