Y fronts 

In Britain, cockney slang for men's underwear - per EastEnder's glossary

"Oy! Don't go out in the street in just your Y-fronts!"

Y fronts by HB Rebecca September 3, 2005

y-fronts 

Male undergarment distinguised by a 'y' shaped penis-flap at the front, which allows easy access for BJs or golden showers.

May cause infertility due to ballsack restriction.

"Do you think I'm sexy if I wear these y-fronts on my head?"

y-fronts by Umbongo - England March 30, 2003

y-fronts 

Typical guys' underwear. There's and opening at the open end of the 'y'.

Last Halloween Roscoe stuck some dingy y-fronts on top of his head and ran down the street shouting,"Pwip!"

y-fronts by Shawn B. September 13, 2003

y-fronts 

old-fashioned underpants so called because the fly is made up of an upside down Y shape allowing quick access but still affording cover

Chris "Y-fronts" B***** MP was so excited by Tony's first election victory that he lowered his trousers in public and started masturbating, while singing Things Can Only Get Better and inviting men to perform oral sex on him.
Call me old-fashioned, but what's wrong with a glass of champagne

y-fronts by theWestHamfan December 15, 2003

y-fronts 

somthing that should never been worn by men under the age of 50

picture it a yong 20-somthing good looking man standing before u in nonting but green Y-FRONTS very disturbing innit?

y-fronts by the girl who wanted to be GOD May 4, 2003

y-fronts 

More accurately the name 'y-fronts' comes from the shape of the undergarment which can be seen as the letter 'y' in much the same way a 't-shirt' may be viewed as the letter 't'.

"Dude, where did you buy those glittery y-fronts? I gots to get me some of those!"

y-fronts by Umbongo - England March 31, 2003

Evil Meat Eating Space Chicken Wearing Sexy Y Fronts 

Not so well know tribe of space chickkens not well know any way but definatly not for their intelligence as they r quite stupid. All their attempts of world domination have failed normally as they have gotton the wrong plannet or foggot what dommination was and went to have a tea break but then fogor what that was to so sat around for 200 years then decding to look up world domination on urbandictionary but then got carried away looking up rude words untill their mums came home and where severly spanked!

The Emperor Of The Evil Meat Eating Space Chicken Wearing Sexy Y Fronts wants to talk about world domination, and ask how to use the bog again!

Evil Meat Eating Space Chicken Wearing Sexy Y Fronts by ---- The Emperor Of The Evil Meat Eating Space Chi October 27, 2003