Unibirth 

Being born on the same day as the number of your birth month.

For example:

12/12/91 or 5/5/91

Hey I have a unibirth ! I was born on 12/12/1991. How about you?

I am a unibirth too! I was born on 5/5/91

Unibirth by Uno125 December 19, 2017

unbirthday 

Statistics prove that you have one birthday, just one birthday every year. But there are three hundred and sixty-four unbirthdays. And this is a reason to gather and cheer.

unbirthday by enken January 10, 2003

unbirthday 

all the days besides your birthday in a year, referred to in Alice in Wonderland also

HAPPY UNBIRTHDAY TO YOU!!!

unbirthday by saxaphoner September 20, 2009

Unbirthday beatings 

Unbirthday beatings are equal to 100 minus your actual age.

These can be given out on any day that is not your birthday, but only once per month per person.

xanthina gives you unbirthday beatings

Unbirthday beatings by xanthina July 4, 2009

unbirth

Fetish involving someone going through a woman's vagina and into the womb, usually coming back out later on. Pretty obviously restricted to cybersex and fantasy art or writing.

Some people on the Internet get turned on by unbirth.

unbirth by Carne Largo October 15, 2003

partial unbirthing 

Fetish of an adult head inside a vagina. Term was created a few decades ago when the fantasy of unbirthing was broken down into total and partial types with partial unbirthing being the only remotely possible form of the unbirthing fantasy. Even then it is an extremely rare activity and the practice of partial unbirthing, as opposed to the fantasy, is not a form of Vore.

See a google search for partial unbirthing

partial unbirthing by A. Akam October 7, 2007

unbirth

cunted

The act of being “put” or putting ones whole self inside an available vagina.
Cedric was once again hammered upon his return home, Sandra took one look at him and swallowed him with her gash! An unbirth reckoning and no mistake!

unbirth by Voidy July 18, 2019