Conjoint Twin Myslexia 

A rare medical condition which involves one half of Siamese twins passing away at birth, thus permanently attaching the corpse to the other one's head.

- Oh my god, dude! He's got a dead fetus on the side of his head!
- Yeah, I know. It's called Conjoint Twin Myslexia. Now stop staring at it.

Conjoint Twin Myslexia by ct^ April 30, 2005

V-Twin 

When two guys fuck one girls pussy at the same time, while coordinating their thrusting such that when one is moving in, the other is moving out; thus simulating the piston action of a V-Twin motorcycle engine. If the timing is not correct it only qualifies as a DV. It is recommended that only good friends attempt this because getting the timing right can be tricky.

Did you and Dave V-Twin that slut from last night?

No, that motherfucker doesn't have any rhythm. We just gave her a DV.

V-Twin by Hank_ November 25, 2010

cosmic twin 

Someone who has a lot of the same interests and similar personality type. If you two were to bang it would be a cosmic event. You and your cosmic twin would be a great couple if you ever got together even though this would probably happen when you two are in your late 60s-early 70s

Gimli: "Yo, Aragorn and Arwen look so cute together!"

Legolas: " I know! They have so much in common too! They must be Cosmic Twins!"

cosmic twin by Morphyne July 12, 2015

Super Twin 

super cool chick that loves the other twin for who they are. will never quit being super twins no matter what.

Monikka: "I LOVE YOU SUPER TWIN!"

Love: "I love you too girrl, you're thee best"

Super Twin by L0V3goes June 27, 2008

Ass-Twin 

Noun- a butt-buddy, the other person in a sexually active homosexual relationship, gay male sex partner.

Did you hear that Christopher, Richard's ass-twin, is going back to San Francisco this weekend?

Ass-Twin by Lingued November 14, 2010

evil british twin 

Often referred to as "Evil Bri'ish Twin" or "Suck on it, you fat twat!" (both said is equally evil British accents), the Evil British Twin will break into your home and piss on your furniture. They probably wear a tight white/blue uniform outfit, and have really stupid, poofy hair. They are annoyingly good at everything and initially come off as charming, but don't be fooled! The Evil British Twin is, in fact, evil.

"Hello, good friend of mine who would never hurt me in any way."
"Piss off! Suck ya mum, you piece of lard!"
"Why are you saying such mean things?"
"Oh, sorry, I'm going through my Evil British Twin arc."

evil british twin by Evil British Twin Hater May 6, 2022

parasitic twin 

In medical circles can refer to twin reversed arterial perfusion, or a subset of conjoint (siamese) twins. Two fetusii develop conjoined, but one (the parasite) does not fully develop and is wholly dependent on his host brother.

In team management refers to a redundant slacker who performs an identical, complete subset of the effort performed by a more capable worker.

a: we have the same job! we're like siamese twins!

b: nah, I do twice as much. you're a parasitic twin

parasitic twin by justsomerandomdude October 14, 2009