1 definition by mw23224

a day celebrated by math geeks across the world on march 14th
Nerd #1: Hey, did you know that the first 50 digits of pi are 3.141 592 6535 8979 323 84 6264 3383 2795 0288 4197 169 3993 751?

Nerd #2: Shut up, I know the first 1,000. Try it next pi day.
by mw23224 March 14, 2007
Get the pi day mug.