Anti-birthday 

A day that occurs near your birthday (usually within 3 or 4 days of it) that really sucks ass for no good reason. Some believe it is meant to balance out the good day that you had on your birthday. Often, an anti-birthday will occur even if your birthday wasn't that great.

John:"Hey Jim! I heard u turned 17 the other day!"
Jim:"ya..." *walks away*
John:"what's with him?"
Joe:"oh dude he's havin his anti-birthday. he's been depressed all day"

Anti-birthday by bSbTbEaK January 13, 2009

21st birthday 

The individual whose birthday it is, gets completely and totally intoxicated with the help of friends/family that eventually leads to uncontrolabe actions and the loss of self-respect and any dignity the individual has.

It was my 21st birthday party last night and my penis burned when I went pee this morning.

21st birthday by Purple Dowg November 16, 2007

Happy Birthday Urban Dictionary! 

n. a greeting addressed to Urban Dictionary on their 11th birthday. Thank you for the words and making me laugh, and for the urban word of the day in my e-mails.

Happy birthday Urban Dictionary!

Happy Birthday Urban Dictionary! by redneck90210 December 10, 2010

Happy Birthday 

When someone says happy birthday and it is not your birthday then that means they got cake or want to give you cake. (Not the dessert kind....)

"Thanks for the cake but it's not my birthday...."
"Happy Birthday ;)"

Happy Birthday by cheekbanger April 29, 2020

18th birthday 

the day where you HAVE to get absolutely wasted!

guy 1: "yo, your 18th birthday is coming up you've got to get wasted bro!!"

guy2: "yeah bro 100%!!"

18th birthday by chonce69 November 19, 2021

Louis Leakey's birthday 

August 7th. The birthday of Louis Leakey who worked in africa and discovered many of the earliest human ancesters. He played a major part in the study of the evolution of humans.

This day is used to educate people on evolution and the evolution of humans and on the findings of paleoanthropology and to fight the false idea of creationsim.

Let's go see the ape man exibit they have out for Louis Leakey's birthday.

Louis Leakey's birthday by Deep blue 2012 May 9, 2010

My Birthday 

Any day in which your girlfriend will let you have anal sex with her. Can be used in past, present and future tenses.

Dude, I bought my girlfriend this awesome choclate browine, and in return it was my birthday!

My Birthday by theoRidGEinal November 21, 2011