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 March 14, 2007

### The Urban Dictionary Mug

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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 March 21, 2005

### The Urban Dictionary Mug

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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 March 15, 2007

### The Urban Dictionary Mug

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A "Math Day" held on March 14—after the first three digits of pi—when mean students with poor attitudes want to get even with their math teachers, by throwing pies at their face.
To celebrate or not to celebrate Pi Day? That's the question schools in crime-infected areas have been wrestling with for years, as teachers try not to let students-turned-"pi-rates" spoil the annual celebration, which aims to reveal the beauty and ubiquity of pi.
via giphy
by March 07, 2017

### The Urban Dictionary Mug

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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 March 14, 2007

### The Urban Dictionary Mug

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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 March 14, 2007

### The Urban Dictionary Mug

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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 March 14, 2007

### The Urban Dictionary Mug

One side has the word, one side has the definition. Microwave and dishwasher safe. Lotsa space for your liquids.

(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!"