In Europe, this day is celebrated on 22nd July. Pi used to be calculated in Ancient Greece as a fraction loosely calculated as 22/7.
Hey Joe, are you going to be having Pizza Pie or Apple Pie to celebrate this year's Pi Day?
by Jonathan FeBland March 14, 2007
Top Definition
March 14th. A "holiday" celebrated by math geeks everywhere. Pi is approximately 3.14, and March the 14th is 3/14.
omg t3h pi day d00d, we are so 1337, pi roxxors t3h boxxors!
by aoiasimsd March 21, 2005
Sorry, but the "true" math geeks are waiting for March 14, 2015 at 9:26 and 53 seconds AM to celebrate. Until then, we'll keep our differential equations and T-distributions to ourselves.
We who celebrate Pi day don't get out very much.
by Jeff42 March 15, 2007
One of several days, notably march 14th, 3/14, and the 22nd of July, representing a common fractional approximation 22/7. It's somewhat of a pointless holiday, but it's always fun to annoy the hell out of people by being able to recite digits of pi from memory.
I'm currently up to 15-ish digits of pi for pi day. 3.14159265358979323
by Jeff the Pirate March 14, 2007
March 14th. A "holiday" celebrated by math geeks everywhere in USA and anywhere else the date is formatted MM/DD/YY. Pi is approximately 3.14, and March the 14th is 3/14 in America.
omg t3h pi day d00d, we are so 1337, pi roxxors t3h boxxors!

I know nothing about the outside world!
by Sam W-P March 14, 2007
(March 14th)
A holiday celebrated by math teachers and geeks everywhere.
March 14th was the chosen day because pi = 3.14.
Since the next three numbers in the sequence are 159, at 1:59, everyone celebrating must say, "Happy Pi Day!"
And please, don't ask how I know.
J0HNNY: Oh my God! It's 1:59! Happy Pi Day!!
GEEK F0LL0WERS: Happy Pi Day!!!
J0CK: WTF?? Where's the pie?
H0HNNY && GEEK F0LL0WERS: Hahaha! Silly dumb kid!
by love x me <33333333333 March 15, 2007
the one and only day that you might actually look forward to going to a math class, as many teachers allow their students to bring in a pie on this special occasion. unless of coarse your math teacher is a fucking nazi, in that case they might just spend the whole period ranting about how cool some retarded number that goes on forever is. yes thats right 3.14 is not technically pi, it goes on and on and on much like ancient old men who think shit like that is cool.
kid 1: "hey man wanna skip next period and smoke a j?"
kid 2: "Yeah... wait today is pi day! we cant skip math class today! we need to smoke now so we can take care of our munchies in there dude."
kid 1: "totally"
by Hannah Mmmmm March 14, 2007
Free Daily Email

Type your email address below to get our free Urban Word of the Day every morning!

Emails are sent from We'll never spam you.