Derived from the abbreviation for "Parental Guidance", PG is used for describing something rude or potentially offensive for which the conversation participants may require adult supervision.

The need to employ a self imposed censorship on utilizing expletives when having a conversation with a friend in the presence of adults and/or uptight people.

Parental Guidance when it comes to movies.

Stands for "Popular Group". It's that group of people who always get invited out to parties, who everyone knows, the pretty girls, the hench lads.

PG stands for Password Guess.

PG is a basketball position which is short for point guard

Also known as a Post Graduate. Someone who takes another Senior year, usually at another high school.

Types of "PGs":
"Talented athlete"-whom is taking an extra year so that they can get a full athletic scholarship from their #1 college pick; spends time taking easy classes and partying/chilling all senior year.
"Extremely smart foreign student"-whom is trying to make it in America and is most likey going to an ivy; spends time in their room all day and night studying.
"Didn't know what else to do"-Since they didn't get recruited for a sport and didn't have the grades to get into a college, they decided to try it over again. But they will fail again and will end up going to a shitty community college. Spends time thinking they are hot shit and trying to hook up with little freshman.