Definition
A private personal detective, employed to gather information about someone.
Origins
From private investigator and its abbreviation P.I., through the homophonic term eye in place of "I", and the use of "eye" as a reference to surveillance.
Also Said As
- private investigator
- PI
How People Actually Use It
When you are fucking your girl from behind and pull out before blowing your load. You then take aim spunking in her eye as she looks back at you wondering why you don't want to give her a cream pie.
"Dude#1:. How come your gf is squinting? Dude#2: I have here the private eye last night."
Source: Urban Dictionary