bum onion 

An unfortunate protrusion from the "chocolate starfish" AKA Farmer, Nobby etc. Can be treated with Preparation H, or a similar pharmaceutical product.

"Oooof! These bum onions give me hell when I ride my bicycle": Attributed to J Sheehan 2004

bum onion by Dr van Truessen January 27, 2004

Mule Onion 

A reference to a woman's backside - specifically a really well-formed one. So called because, as we all know, crossing a mule and an onion results in "an ass that'll bring tears to your eyes".

"Damn, look at the mule onion on that one!"

Mule Onion by Heathen 2.0 April 29, 2008

Counterfeit Onion Rings 

Also know as Funions. Although delicious they leave you feeling empty inside.

Guy1: Damn these counterfeit onion rings are tasty!
Guy2: Yeah but they make me feel empty...
Guy1: Whatever just hand me the bag!

Counterfeit Onion Rings by Shaado November 14, 2010

Double Onion 

The process of having sexual intercourse where both participants are crying. Can be applied as a Triple Onion if a threesome is being partaken and so on. A Single onion is the most common.

"Hey man, heard you got lucky last night! How was it?"
"Turned into a bit of a Double Onion but It was still magical."

Double Onion by Classic Alfredo December 28, 2016

boofed onion 

The smell of urine that has been sitting and becomes rancid over time.

That room smells like boofed onions because Timmy doesn't clean the urine on his bed.

boofed onion by j76815 March 27, 2019

The Weird Onion

Unique sexual fetish in which the male inserts a peeled onion into the vagina of the female whilst forcing the peelings into her nose. The pleasure is often derived from the extreme tingling sensation within the nasal cavity

Bro! Me and this chick from the club did the weird onion last night *high five*

The Weird Onion by BlueKittenZz December 2, 2014

Emperor's Onion 

A stink so bad it makes the paint on the walls peel, like an onion makes your eyes water.

Adam (Gets out of the washroom) - Aw man
Frank - Choke another donkey?
Adam - Nope, dropped me an Emperor's Onion for the next guy..

Emperor's Onion by Kallerack March 23, 2019