I know we’re joking… but just in case people don’t know, π, despite what we call it in English, is the letter “p”, which ought to be said “pee”, and was chosen for “periphery”. Though “perimeter” could be used as as well. Because even though we have the special word “circumference” for the perimeter of a circle, pi is the ratio of a circle’s perimeter to its diameter. As in, take diameter, multiply by magic constant p, get perimeter.