pi
n 1: the ratio of the circumference to the diameter of a circle
[syn: {3.14159265358979323846...}]
2: someone who can be employed as a detective to collect
information [syn: {private detective}, {PI}, {private eye},
{private investigator}, {operative}, {sherlock}]
3: the scientist in charge of an experiment or research project
[syn: {principal investigator}, {PI}]
4: the 16th letter of the Greek alphabet