As an undergrad there is a lot I don't know. Most of what I don't know can be covered by time, or research, or both.

But since I've been writing here I've not for the life of me been able to figure out what the F- 'PI' means.

I found a list of 184 potential definitions for the acronym PI, but none helped [here]. Maybe it's something that differs this side of the equator, but could someone please put me out of my misery? 

Or, alternatively, Primary Investigator.