HAPPY PI DAY!

lol :D

HAHA slip oh man....haha

Here is the awnser I was looking for:

-the 16th letter of the Greek alphabet

this is what Wikipedia says, The constant is named "π" because it is the first letter of the Greek words περιφέρεια 'periphery'[1] and περίμετρος 'perimeter', i.e. 'circumference'.